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报告题目:基于低维半导体的偏振光探测及图像传感器
报告人:赵凯
博士(中科院半导体研究所)
时间:2021年4月6日(星期二)下午5:00
地点:光电所二层报告厅
摘要:
基于各向异性半导体材料的宽光谱和超快速光响应偏振光探测器在民用领域具有广泛的应用,近年来备受关注。我们以宽光谱的偏振光探测及图像传感为目标,分别研究了以Sb2S3和-Ga2O3为代表的可见光及紫外日盲区的偏振光探测和成像。其中Sb2S3具有低对称的晶体结构和特殊的电子能带结构,这使得它在可见光及近红外区域具有较强的偏振光探测优势。我们通过硫辅助的物理气相沉积方法制备了Sb2S3纳米线,从实验和理论两方面系统地研究了Sb2S3纳米线的光学,振动和光电各向异性,并探索了Sb2S3纳米线在偏振成像传感领域的应用。同样以-Ga2O3为代表的日盲紫外探测器在偏振光识别和偏振光源检测上表现出优异的性能。
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报告题目:空间激光干涉仪关键技术研究进展
报告人:李玉琼 副研究员(中科院力学所)
时间:2021年4月6日(周二)上午10:00
地点:光电所二层报告厅
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报告题目:基于量子互联网的量子存储和中继研究
报告人:曹明涛
副研究员(中科院国家授时中心)
时间:2021年3月5日(周五)11:00
地点:光电所二层报告厅
摘要:
量子通信技术的绝对安全性使其在国防和军事上有广阔的应用前景,其代表未来通讯技术发展的战略方向,是目前世界各国关注的研究焦点。基于量子存储的量子中继技术,实现不同量子节点之间量子态的同步、提纯和交换,旨在解决长距离量子通信的信息损耗问题,是组成未来量子通信网络的重要核心单元。本报告将基于欧盟“量子网络互联网联盟”的量子中继专项,围绕高光学厚度的冷原子系统,介绍高效率量子存储的相关研究工作。
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报告题目:基于拉曼增益的高功率级联泵浦随机光纤激光器研究
报告人:王泽晖 博士(
清华大学)
时间:2021.2.2(周二)上午10:00
地点:光电所二层报告厅
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报告题目:铋硫族化合物Bi2S3和聚硫化物在柔性水系锌离子电池中的应用
报告人:赵玉伟
博士(香港城市大学)
时间:2021.2.1(周一)上午11:00
地点:光电所二层报告厅
摘要:
由于水系可充电锌离子电池(ARZIBs)具有成本低、安全性高、寿命长等特点,其相较于非水系锂离子电池有很大的优势。到目前为止,已经报道的正极材料包括钒基氧化物、锰基氧化物、普鲁士蓝类似物、有机物等。然而,有限的正极材料阻碍了它的进一步的发展。因此,对于高容量和长寿命的正极材料的探索迫在眉睫。
我们将铋硫族化合物Bi2S3应用于锌离子电池,开发了离子液体增强聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸盐(PEDOT:PSS)涂层。这层液膜具有稳定Bi2S3电极,提供高导电性以及抑制颗粒粉碎和硫溶出三种作用,是人工固液间相(SEI)。Bi2S3的理想容量和聚合物的优异性能协同作用提供了275
mAhg-1的容量和出色的循环稳定性,5300次循环后容量保留率为95.3%。研究揭示了Bi2S3向六方ZnS可逆转化的机理。基于高浓盐电解液/聚丙烯酰胺水凝胶制备的准固态电池具有较高的能量密度(315
Whkg-1)。作为演示,单个电池可以为数字湿度温度计供电超过14小时48分钟。这项工作完成了结构完整性与稳定的界面化学相结合的演示。
硫正极在Li/S电池、Na/S电池、Mg/S电池、Al/S电池等体系中得到了广泛的研究。然而,迄今为止,锌/硫化学从未被报道过。我们报道了一个由PEDOT:PSS包裹的4-(3-丁基-1-咪唑)-1-丁烷磺酰离子液体(IL)组成的“液体膜”激活的水系Zn/聚硫体系,IL中CF3SO3−离子作为Zn2+转移通道。此外,PEDOT:PSS网络存储IL形成Zn2+转移通道同时也有利于增强多硫化物正极结构稳定性。Zn/聚硫体系在0.3
Ag-1下表现出1148 mAhg-1的超大容量和724.7
Whkg-1的正极能量密度。放电过程中以S62-为主被Zn还原为S2-(S62-→S2-)。在充电阶段,这些短链被氧化形成长链ZnxLiyS3-6。进一步优化的高浓度盐电解质可用于提高电池的可逆性,在1
Ag-1下,超过1600个循环后电池的容量保持为204
mAhg-1。开发的水系锌/硫化学采用实用的方法,展现了优越的电池性能,为硫基电池的研究发展的提供了新的平台也潜在地为解决其他金属/硫电池存在的问题提供了方法。
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报告题目:侧信道密码分析与微体系结构安全
报告人:高宜文 博士 (
新加坡国立大学)
时间:2021.1.15(周五)上午10:00
地点:光电所二层报告厅
(腾讯会议ID:915 160 785)
摘要:
侧信道密码分析技术广泛应用于密码设备物理安全性分析和评估,它通过获取密码算法运行过程中所泄漏的侧信息,恢复或破解密码算法机密信息。基于微体系结构的侧信道分析是通过利用密码设备的微体系结构特征所提供的信息泄漏提升侧信道分析能力的攻击方法。GPU密码实现是通信和互联网领域密码应用的一种重要解决方案。GPU硬件架构的基本特点之一是通过多核并行计算提高系统的吞吐量。这一基本特点决定了GPU应用程序的多任务并行执行模式。支持这种多任务并行执行模式的硬件设计提供了特殊的线程同步和资源共享机制,这些机制的设计在优化系统性能的同时也带来的新的安全威胁。我们的研究表明,通过利用这些硬件固有机制,可以有效提升侧信道密码分析的效率。
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报告题目:基于深度学习和磁共振成像的颅内动脉瘤破裂风险因素研究
报告人:张妙其
博士(清华大学)
时间:2020年12月21日(周一)上午10:00
地点:光电所二层报告厅
摘要:
颅内动脉瘤是自发性蛛网膜下腔出血最常见原因,首次破裂出血后,往往在数小时、数天内发生再次破裂出血,是导致病人死亡和残废的主要原因。目前最佳的未破裂颅内动脉瘤的处理策略仍有争议,未破裂颅内动脉瘤的破裂风险是是否手术的决定性因素。因此,动脉瘤破裂风险的预测具有巨大的临床价值。本项目拟设计一套全新的基于深度学习和磁共振成像的颅内动脉瘤破裂风险预测方法。
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报告题目:超冷锂锶混合实验进展
报告人:叶祝雄
博士(清华大学)
时间:2020年12月17日(周四)下午5:00
地点:光电所二层报告厅
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报告题目:基于神经网络的状态控制
报告人:田雷 博士
(清华大学)
时间:2020年12月17日(周四)下午4:00
地点:光电所二层报告厅
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报告题目:千赫兹引力波探测器
报告人:缪海兴
教授(清华大学)
时间:2020年12月10日
17:00-19:30
地点:腾讯会议 581 415
372
摘要:
引力波探测开启了天文观测的一个新窗口,开拓了引力物理及高能天体物理的研究途径。至今我们已经多次观测到双黑洞和双中子星的引力波源,其中双中子星事件GW170817是首次联合了电磁波全频段的共同观测,这革新了我们对中子星物理及重元素起源的理解。然而此次观测未能揭示蕴含丰富新物理的双中子星并合过程。因为并合产生的引力波在千赫兹附近,Advanced
LIGO及VIRGO激光干涉仪引力探测器在千赫兹的噪声过高而淹没了此信号。此频段的主要噪声来源于光量子涨落导致的量子噪声。如何降低量子噪声是千赫兹引力波探测器研究的核心。本报告将介绍此方向的一些研究发现。其中包括(1)我们可以结合高光强、量子压缩态及量子相干反馈将Advanced
LIGO在千赫兹附近的灵敏度提高一个量级以上;(2)千赫兹引力波探测器的最优臂长约为20公里,正好介于欧洲10公里Einstein
Telescope和美国40公里的Cosmic Explorer之间,这为中国发展地面引力波探测提供了契机。
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报告题目:半导体微腔激光器模式调控及应用
报告人:黄永箴
研究员(中国科学院半导体研究所)
时间:2020年11月2日(周一)上午10:30
地点:光电所二层报告厅
摘要:
报告将介绍光学微腔及应用,正方形微腔激光器的模谱调控,变形六边形微腔激光器模式调控及双模作用自发混沌现象,以及正方形与法珀腔形成的耦合腔激光器的光双稳及单模工作特性。
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报告题目:Error-mitigated quantum computing with
near-term quantum hardware
报告人:袁骁
助理教授(北京大学前沿计算中心)
时间:2020年10月28日(周三)上午10:00
地点:光电所二层报告厅
摘要:Realizing a
universal quantum computer is challenging with current technology.
Before having a fully-fledged quantum computer, a more practical
question is what we can do with current and near-term quantum hardware.
Focusing on the noisy-intermediate-scaled-quantum regime, we present
variational quantum algorithms for solving static and dynamic problems
of many-body physics. We show how to suppress device errors due to
implementation imperfection on both digital and analog quantum
computers. The algorithms are also applicable to other tasks, including
quantum machine learning, quantum sensing, and quantum error correction.
With the rapid development of quantum hardware, error-mitigated
variational quantum algorithms may finally enable genuine quantum
advantage demonstration in the noisy-intermediate-scaled quantum era.
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报告题目:Optomechanical instabilities in laser
interferometer gravitational wave detectors
报告人:Jian Liu
(Postdoctoral researcher, Max-Planck Institut für Gravitationsphysik)
时间:2020年10月24号(周六)上午9:30
地点:光电所二层报告厅
摘要:I am
currently a postdoctoral researcher at the Max-Planck Institut für
Gravitationsphysik (Albert Einstein Institute), working on commissioning
of a 10 m prototype gravitational wave detector which aim to achieve
quantum noise only limited sensitivity.
I worked on instrumentation of gravitational wave physics. In
particular, I did research in Gingin lab of University of Western
Australia, which hosts an 80 m suspended optical cavity. My research
interests include controlling and locking acquisition of high-power
suspended cavity as well as preventing radiation pressure induced
instabilities such as parametric instability and angular instability.
I went to LIGO Hanford as a fellow for half a year where I worked on
designing and characterizing the new bowtie pre-mode-cleaner for O3 run
which is now being installed. I worked on the designing of a triangular
cavity for beam jitter noise attenuation for future science run and LIGO
A+ project. I was also involved in general commissioning and detector
characterization while I was in LIGO.
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报告题目:Angular stripe phase in
spin-orbital-angular-momentum coupled Bose condensates
报告人:Xiao-Long
Chen (陈小龙) 博士后 清华大学
时间:2020年10月22日
下午4:00-5:00
地点:光电所二层报告厅
摘要:In this
talk, I will present a superfluid with supersolid-like properties, i.e.,
angular stripe phase, realized in a pancake-like spin-1/2 Bose gas with
spin-orbital-angular-momentum coupling. A rich ground-state phase
diagram, including the vortex-antivortex pair phase, the half-skyrmion
phase, and two different angular stripe phases, will be depicted. The
stripe phases feature a modulated angular density-density correlation
with a sizable contrast and can occupy a relatively large parameter
space. The low-lying collective excitations, such as the dipole and
breathing modes, show distinct behaviors in different phases. The
existence of the stripe phase is also clearly indicated in the energetic
and dynamic instabilities of collective modes near phase transitions.
Our predictions of the angular stripe phase could be readily examined in
current cold-atom experiments with 87Rb and 41K.
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报告题目:Many-body Localization From Dynamical
Gauge Fields
报告人:Zhiyuan Yao
(么志远) 博士后 清华大学
时间:2020年10月22日
下午5:00-6:00
地点:光电所二层报告厅
摘要:Gauge theory
not only plays a central role in describing fundamental interactions in
nature but also often emerges as the low-energy effective theory of
various condensed matter systems. Starting from about a decade ago,
simulating synthetic gauge fields has also become a main research topic
in cold-atom physics. Inspired by a recent experiment [Nat. Phys. 15,
1168 (2019)] that realized a dynamical gauge system with a Z2 gauge
symmetry in a double-well potential, we propose a method to generalize
this model from a single double well to a one-dimensional chain. We show
that although there are no disordered potentials in the original model,
the phenomenon of many-body localization can occur. The key ingredient
is that local gauge charges play the role of different disorder
configurations, which becomes clear after exactly mapping our model to a
transverse Ising model in a random longitudinal field. We provide
extensive numerical evidence to show that both the ergodic regime and
the many-body localized regime exist in this model.
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报告题目:Towards Optimal Quantum Neural Network
Structure
报告人:Yadong Wu
(吴亚东) 博士 清华大学
时间:2020年10月22日
下午3:00-4:00
地点:光电所二层报告厅
摘要:Machine
learning based on neural networks has recently provided significant
advances for many practical applications. In physics, one natural
application is the study of the quantum many-body systems. There are
several works about using quantum computation or quantum neural networks
to enhance conventional machine learning tasks. Intuitively, for the
deep learning, we thought the more complicated the neural networks,
better the expressions. But we can’t increase the depth of the neural
network infinitely. So here is the question, for the finite depth of a
neural network, or more specifically, for the same two-bit gate number
of a quantum neural network, what kinds of circuit structure can give us
a good prediction after training. In this work, we use two qualities of
a quantum circuit to describe the expression ability of a quantum
circuit structure. One is the tripartite information, other is the
operator size. We build a few different kinds of quantum circuit
structures and compare the learning ability of these structures. After
learning a quantum task and a classical task, we find the more scramble
of a circuit, the better it can learn. What’s more, we design ‘the super
circuit’, which has the best learning ability.
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报告题目:宇称-时间光力学
报告人:景辉
教授 (湖南师范大学)
时间:2019.12.12(周四)上午11:00
地点:光电所二层报告厅
摘要:作为光学发展史上的里程碑之一,光力学在引力波探测、光镊、量子态操控与量子信息处理等方面已经展示出广阔而重要的应用前景,同时,具有宇称-时间对称性的光学系统在奇异点处的物性发生剧烈变化,出现诸多新奇效应,有望为量子精密测量带来颠覆性的新技术。我们结合两个领域提出宇称-时间光力学理论,预言了超低阈值声子激光、反转光力透明、力学灵敏传感等新奇效应,理论预言已获得美国华盛顿大学实验验证。我将汇报这方面的工作及新进展,如量子奇异点效应,量子非互易效应,以及反宇称-时间对称破缺的陀螺仪。
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报告题目:Simulating
chiral phenomena with ultracold atomic gases: from s-band to p-band,
from real-space to momentum-space
报告人:李永强
副教授(国防科技大学)
时间:2019.10.24(周四)下午5:00
地点:光电所二层报告厅
摘要:The
interplay of spin, orbital, and charge degrees of freedom is one of the
cornerstones of correlated quantum materials. Many intriguing quantum
phases of electronic matter can be attributed to higher order electronic
orbitals and spin-orbital interactions, e.g., in exotic
superconductivity in pnictides and strontium ruthenates, as well as in
various topological insulators and Weyl semimetals. In this talk, we
mainly focus on two issues:
First, we propose a mechanism of spontaneous generation of spin
angular-momentum coupling with spinor atomic bosons loaded into
p-orbital bands of a two-dimensional optical-lattice. This spin angular
momentum coupling originates from many-body correlations and spontaneous
symmetry breaking in a superfluid, with the key ingredients attributed
to spin-channel quantum fluctuations and an approximate rotation
symmetry. The resultant spin angular-momentum intertwined superfluid has
Dirac excitations.
Second, we propose to study the many-body chiral edge current of
ultracold gases in a momentum-space superradiance lattice by coupling
with a Rydberg state. We explore stationary and dynamical properties of
the momentum-space lattice in an artificial magnetic field. The
many-body ground states support both chiral and anti-chiral edge
currents in momentum space. Their stability against strong interactions
is verified by a dynamical mean-field simulation. We show that the
interplay of the interaction and chirality leads to correlated chiral
dynamics, where an interaction-induced excitation blockade in momentum
space suppresses the edge currents. When incorporating an effective
decay to the lattice, we find that excitation transportation, whose
dynamics is governed by a dissipative Bose-Hubard model, can be
prohibited by a strong local dissipation, as a result of the quantum
Zeno effect.
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报告题目:量子力学与哲学(上、下)
报告人:张天蓉
科普作家
时间:2019年10月14日(周一)下午4:00(上)
2019年10月15日(周二)下午4:00(下)
地点:光电所二层报告厅
摘要:从简单回顾量子力学引发的几个哲学问题开始,然后重点介绍
“自由意志定理”,简单叙述人类有关自由意志的思考,宗教及伦理方面的意义等,最后解读2006年普林斯顿两位数学家(John
Conway和Simon Kochen)所证明了的一个量子力学数学定理,即自由意志定理:“如果人有自由意志,那么亚原子粒子也有自由意志。”
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报告题目:统计物理里的病态极限
报告人:陈昌晔 教授(北京航空航天大学)
时间:2019年10月14日(周一)下午5:00
地点:光电所二层报告厅
摘要:本文揭示了某些统计物理里的多变量极限是数学上病态定义的,沿着这条路线,本文说明借助于重新定义、重新解释和重新计算这些极限,非平衡态气体动力学可能获得重大进展。
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报告题目:继续量子革命
报告人:施郁 教授 (复旦大学)
时间:2019.9.30(周一)上午10:00
地点:光电所二层报告厅
摘要:量子力学是微观物理学的基本理论框架。它确立90年来,在物理学基础与应用的方方面面,取得了一个又一个的成功。量子力学还在进一步发展中,被称为“第二次量子革命”。本人认为量子革命一直在持续地发生,并将继续下去,可能会引来“量子革命的第二次高潮”。
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报告题目:Spontaneous
pattern formation in a driven Bose-Einstein Condensate
报告人:Prof.
Cheng Chin (James Franck Institute, Enrico Fermi Institute and
Department of Physics,University of Chicago)
时间:2019年9月9日(周一)下午5:00
地点:光电所二层报告厅
摘要:Pattern
formation is ubiquitous in nature, from morphogenesis, cloud formation
to galaxy filamentation. More often than not, patterns arise in a
medium far from equilibrium due to the interplay between dynamical
instability and nonlinear wave mixing. We report, based on momentum and
real space pattern recognition, spontaneous formation of density
patterns with D2, D4and D6 symmetries in Bose-Einstein condensates with
atomic interactions driven at two frequencies. The symmetry of the
pattern is controlled by the ratio of the frequencies. The D6 density
waves, in particular, arise from a resonant wave mixing process that
coherently correlates and enhances all 6 excitations that support the
symmetry.
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报告题目:Non-equilibrium
physics in a Strongly Interacting Fermionic Superfluid
报告人:Kuiyi
Gao(Physikalisches Institut, University of Bonn)
时间:2019.8.19(周一)下午5:00
地点:光电所二层报告厅
摘要:Ultra-cold
Fermi gases with tunable interactions have been widely used to
investigate the BEC-BCS crossover in the last decade. Dynamics and
thermalization in strongly interacting atomic Fermi gases was proposed
to study excitations and pairing in superconductivity. In this talk, I
will show our experiments in exploring non-equilibrium dynamics in
strongly interacting Fermi gas of 6Li atoms. With a periodic modulation
of the order parameter, the amplitude mode with frequency around 2 ? /h
was observed. With interaction quenches around unitary limit, dynamics
and thermalization beyond collisionless BCS theory were found.
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报告题目:Fracton
topological order
报告人:叶鹏
教授(中山大学)
时间:2019.8.12(周一)上午11:00
地点:光电所二层报告厅
摘要:Fractons
are a class of topological excitations whose spatial mobility is highly
restricted. In other words, it is impossible to construct a quantum
operator that is able to “move” the fraction point-like particle freely.
In this talk, I will introduce our recent work on “fracton topological
order” especially focusing on the generalization of exactly solvable
models and fractonic many-body physics.
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报告题目:Complete
spin filtering in molecular junctions by quantum interference
报告人:Dr.
Dongzhe Li (University of Konstanz)
时间:2019年7月11日(周四)下午5:00
地点:光电所二层报告厅
摘要:Generating
efficient and highly spin-polarized currents through nanoscale junctions
is essential in the field of nanoelectronics and spintronics. In this
talk, coupling state-of-the-art ab initio electron transport
calculations and shot noise measurements, I will give the first
demonstration to obtain complete spin filtering in molecular junctions
based on symmetry arguments and spin-dependent quantum interference
effects. In particular, a mechanical strain can be used to modify the
nanojunction symmetry switching on or off new conduction channels. I
will first illustrate the physical mechanism on the basic molecular
junction of benzene and generalize it in vanadocene junction to explain
recent shot noise measurements of an almost fully open spin-polarized
transmission channel. Remarkably, the majority-spin conductance is
completely suppressed due to destructive quantum interference, resulting
in perfect spin filtering. Therefore, a single molecule act as a
half-metallic conductor although free organic molecule is actually an
insulator. These findings pave the way for spin transport manipulations
by quantum interference at the single nanometer scale.
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报告题目:Multipartite
entanglement: from triplet photon generation, coupled nonlinear
waveguides to frequency coding
报告人:Prof.
Kamel Bencheikh (Centre of Nanoscience and Nanotechnology – C2N,
Université Paris-Sud - Université Paris-Saclay, France)
时间:2019年6月13日(周四)下午5:00
地点:光电所二层报告厅
摘要:Entanglement
has morphed from thought experiments into laboratory reality in a
century and is the cornerstone of future quantum technologies. The
enormous potential of entanglement to secure and parallelize information
processing and transmission can only be achieved by relying on
innovative sources and platforms and custom detection systems. I will in
my talk address the issue of the sources we are exploring in our group
at C2N.Triple photon generation It is based on a third order nonlinear
optical interaction and it is the most direct way to produce pure
quantum three-photon states. These states can exhibit three-body quantum
entanglement and their statistics go beyond the usual Gaussian
statistics of coherent sources and optical parametric twin-photon
generators, offering new tools for quantum mechanics. Nonlinear
waveguide arrays provide an integrated platform for quantum information
compatible with telecom wavelength. By engineering their design,
controlling the coupling strength between adjacent waveguides and the
strength of the nonlinearity, we can generate entanglement among the
modes propagating in the arrays.The third avenue we are exploring in our
group is the frequency domain quantum information where qubit or high
dimensional quantum bits are encoded on distinguishable optical
frequencies.During my talk, I will discuss these three avenues focusing
on our results on triple photons states and coupled nonlinear waveguides
and will mention our starting project on frequency domain quantum
information.
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报告题目:光致超声推动流体和激光驱动微流控泵
报告人:王志明
教授(电子科技大学)
时间:2019年5月22日(周三)下午5:00
地点:光电所二层报告厅
摘要:如何有效地对宏观液体进行精细操控对于微流体芯片实验室、微制造、生物芯片、医药和生命科学是十分重要的研究领域,而利用激光驱动液体流动更是科研界的重大难题。光子的动量传输作用极为微弱,激光透射水的光热效应产生的表面张力差也很微弱,无法实现对宏观液体的推动。王志明教授团队提出了一种全新的光流体学机理:声效应和声波驱动流体效应。通过脉冲激光入射装有金纳米颗粒水溶液的比色皿,首次利用脉冲激光在水中实现持续高速达4
cm/s的水流喷射。在此基础上,课题组制成了一种不包含微细加工结构和活动组件的新型微流控泵。该泵基于光致超声驱动流体的原理,通过简单的金注入石英基板制成。在脉冲激光激发下,石英基板上的任意一个点即可产生定向的长时间持续的超声波以推动流体运动。通过程序化地操控激光束可以非常容易地实现单泵,动态泵和多泵模式。这种激光驱动的微流控泵为微泵技术的发展打开了新的大门,为微流控泵的集成化和多功能化应用提供了新的机会,推动了微流控芯片技术,超声药物输送,医疗手术等领域的发展。
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报告题目:Precision
measurements beyond standard quantum limit in vapor cells
报告人:肖艳红
教授(复旦大学物理学系)
时间:2019年5月17日(周五)下午5:30
地点:光电所二层报告厅
摘要:Measurements
lay at the foundation of physical science, and their ultimate precision
is normally set by the standard quantum limit (SQL). Entangled states
such as spin squeezed states, squeezed light can be used to break such
limit, but previous experiments have largely been proof-of-principle,
i.e., the absolute precision of those measurements, although beyond SQL,
is relatively low. We have recently achieved spin squeezing for more
than 100 billion atoms in a macroscopic vapor cell, exceeding the best
angular resolving power in any spin squeezed state so far by 1000 times,
with the aid of adiabatic pulse control and motional averaging. In a
similar setup, a femtotesla level atomic magnetometer operated at room
temperature was demonstrated, using a new weak-measurement spectroscopy.
These results show potential benefits of entangled states even in
practical and high-precision systems. In parallel, we are developing
novel quantum light sources such as squeezed light array, quantum
correlated beam array, by employing coherent diffusion of polaritons in
vapor cells. Such light sources will find applications in quantum
information science as well as quantum metrology.
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报告题目:从团簇科学到原子制造
报告人:宋凤麒
教授(南京大学物理学院)
时间:2019年5月13日(周一)下午4:30
地点:光电所二层报告厅
摘要: 原子制造是从原子极限水平制造材料与器件的新兴学科,是人类微制造趋势发展的必然趋势。团簇是具有若干个原子的结构和性质相对稳定的原子聚集体,是原子制造研究的一个方向。本报告给大家汇报南京大学团簇研究组逐渐走向原子水平的一些成果:
1)原子团簇束流与质量选择技术
2) 单团簇器件制造与输运研究
3) 等离激元的原子截止极限
4) 团簇修饰拓扑绝缘体器件与电子输运研究
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报告题目:激光医学在临床中的应用
报告人:顾瑛
中国科学院院士(中国人民解放军总医院)
时间:2019年5月9日(周四)上午10:00
地点:光电所二层报告厅
摘要: 顾瑛,激光医学专家,中国科学院院士,中国人民解放军总医院激光医学科主任医师、教授、博士生导师,量子光学与光量子器件国家重点实验室学术委员会委员。顾瑛院士主要从事激光在临床医学中的应用研究。完成了血管靶向光动力疗法的理论和机理、药物和设备、技术和方法、应用和规范的系统性研究,开创了血管靶向光动力治疗的新学术方向和应用领域。合作研发出国家化学1.1类血管靶向光动力治疗新药——海姆泊芬。主持制定了中国首部激光医学临床技术操作规范和诊疗指南。发表学术论文180余篇,撰写专著1部。科研成果获国家发明奖1项、军队科技进步二等奖2项。
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报告题目:自旋轨道耦合冷原子中的新奇量子相
报告人:韩伟
副研究员(中国科学院国家授时中心)
时间:2019年5月8日(周三)下午4:30
地点:光电所二层报告厅
摘要:超冷原子气体是将稀薄原子团冷却到绝对零度附近,来研究体系的新奇量子现象和遵循的物理规律。超冷原子气体研究已成为当前原子分子物理、非线性与量子光学、统计和凝聚态物理等学科的重要交叉领域,无论是从基础物理研究层面(如量子调控、量子模拟、探索新物态等),还是从发展高新技术层面(如原子激光、原子干涉仪、原子芯片、原子钟、量子计算机等)都具有十分重要的意义。本报告将结合超冷原子气体最新研究进展和国际前沿动态,介绍自己在自旋轨道耦合超冷原子新物态(如手性超固态)、奇异拓扑元激发(如双量子自旋涡旋态、自旋畴壁)、新奇量子效应等方面的代表性研究工作。
简介: 韩伟,中国科学院国家授时中心副研究员,中国科学院大学硕士生导师。于2013年获得山西大学理学博士学位。长期从事超冷原子物理、玻色-爱因斯坦凝聚等方面的研究,在超冷原子新物态以及奇异拓扑元激发等方面做出了一系列工作。作为项目负责人先后主持国家自然科学基金项目(2项)和省部级科研项目(2项目)。近年来在Physical
Review Letters, Physical Review
A等期刊发表SCI学术论文20余篇。参与撰写冷原子物理学术著作一部,由《World Scientific Publishing
Company》出版。
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报告题目:Strong-field,
ultrafast, and attosecond physics and the semiclassical models
报告人:Dr.Nikolay
Shvetsov-Shilovskiy (Institute for Theoretical Physics, Leibniz
University Hanover)
时间:2019年4月30日
(周二) 下午4:00
地点:光电所二层报告厅
摘要:Strong-field,
ultrafast, and attosecond physics are new and promising research
avenues resulting from remarkable developments in laser technologies
during the last three decades. In accord with the common definition, a
"strong" laser field corresponds to the electric field strength
comparable to that acting on an electron in a hydrogen atom. The
"ultrafast" time scales typically refer to laser pulses of femtosecond
duration. In contrast to this, attosecond science studies dynamics of
quantum systems on the timescale less than a femtosecond. These time
scales imply a great diversity of possible applications, both is
science and technology. We present a brief overview of these
applications and discuss the nonlinear phenomena originating from
interaction of strong laser radiation with atoms and molecules.
Semiclassical models employing classical equations of motion to
describe the electron motion in the continuum are one of the widely
used theoretical approaches in strong-field physics. We overview
trajectory-based simulations of the main strong-field phenomena.
Finally, we discuss semiclassical perspectives of strong-field
photoelectron holography - a new and promising method capable to
visualize molecular dynamics in real time.
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报告题目:Phase
transition in a spin-orbital-angular-momentum coupled Bose-Einstein
condensate
报告人:江开军
研究员(中科院武汉物理与数学研究所)
时间:2019年4月17日(周三)下午4:30
地点:光电所二层报告厅
摘要:Coupling
between particle’s spin and orbital motion (linear momentum or orbital
angular momentum) is ubiquitous in atoms, photons, solid materials and
many other systems. It contributes to the topological properties like
quantum-Hall effect in solid materials and electronic fine structure in
atoms. Ultracold atoms with a high tunability provides an ideal
platform to study spin-orbit (SO) coupling. Spin-linear-momentum (SLM)
coupling has been observed in quantum gases and subsequently a variety
of exotic quantum states have been explored. While the experimental
study on the other kind of SO coupling, namely the
spin-orbital-angular-momentum (SOAM) coupling, is still lacking.
In this talk, I will report the experimental observation of the
ground-state phase diagram of the SOAM coupled Bose-Einstein
condensate. By inducing a Raman transition using a pair of Gaussian and
Laguerre-Gaussian (LG) laser beams, we realize SOAM coupling of
ultracold atoms. We observe phase transitions when the two-photon Raman
coupling strength or detuning approaches the critical value. The phase
transitions are classified as the first order, which feature a
discontinuous jump of the angular momentum (OAM) and the spin
polarization. We demonstrate the hysteresis loop across the first-order
phase transition. The role of interatomic interaction on the phase
transition is also elucidated.
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报告题目:用于空间引力波探测的星间激光干涉测量技术
报告人:叶贤基 教授/副主任(中山大学物理与天文学院 天琴中心)
时间:2019年4月2日(周二)下午3:00
地点:光电所二层报告厅
摘要:
经过100年的努力,LIGO研究组科学家在2016年宣布测到了爱因斯坦广义相对论的最后一项预言-引力波。引力波探测将验证强引力场下的引力理论,并开启引力波天文学新纪元。地面引力波天线只能探测频率高于10Hz的引力波信号,而空间引力波天线能探测更低频、更稳定、更多类型的引力波源,是研究引力波天文学的最重要探测手段。本报告将介绍空间引力波探测所需要的核心关键技术-星间激光干涉测量技术,内容包含:基本原理、系统组成、指标需求,天琴研究中心在星间激光干涉测量技术研究的最新进展。
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报告题目:囚禁离子量子模拟与计算
报告人:王钊 副研究员(中山大学)
时间:2019.3.22(周五)下午5:00
地点:光电所二层报告厅
摘要:
囚禁离子系统在各物理系统中可控性很强,态制备及测量保真度最高的物理系统,因此最有可能实现大规模量子计算。目前在单个离子阱系统内可以实现超过容错量子计算阈值的高保真度态制备、态测量、单(双)比特高保真度逻辑门操作,因此提高扩展性是离子系统最重要发展方向。报告介绍了离子阱量子系统的基本实现原理和方法,提高纠缠量子比特数量、实现量子网络的主要方法,以及目前实验进展。
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报告题目:Quantum gate teleportation between separated zones of a
trapped-ion processor
报告人:万雍 博士(National Institute of Standards and Technology,
Boulder, USA)
时间:2019年3月2日(周六)上午10:00
地点:光电所二层报告厅
摘要:Scaling
up trapped-ion quantum information processors implies that
above some size, qubits will likely need to be distributed
across multiple processing zones. Harnessing the full power
of such an architecture for quantum information processing
requires a method to connect qubits in separate locations.
The “quantum charge-coupled device” architecture allows to
couple distant qubits by first physically moving them
together, but at the same time imposes overhead from time
spent on shuttling ions. An alternative solution is to
employ a teleported two-qubit entangling gate that uses only
local operations in two separate locations, classical
communication between these locations, and a shared
entangled qubit pair as a resource. This approach has been
demonstrated probabilistically in photonic systems with
post-selection and only recently performed deterministically
between two superconducting cavity qubits by means of an
entangled pair of transmons. Here we demonstrate a
deterministic teleported CNOT gate between two beryllium ion
qubits in spatially separated zones of a segmented Paul
trap, using an entangled pair of magnesium ion qubits as the
resource. We perform full process tomography on the two
beryllium ions, and infer a 95% confidence interval [0.845,
0.872] for the CNOT entanglement fidelity using maximum
likelihood (ML) estimation. To characterize consistency with
a single quantum process and to discover unchecked
fluctuations, we apply a likelihood-ratio test to the
tomography data, which indicates an unexpected level of
inconsistency. We verify through numerical simulation and
independent measurements on the experimental setup that slow
drifts in some laser beamlines was likely the cause of this
inconsistency, suggesting the importance of such consistency
checks in addition to other benchmarking techniques. Our
experiments combine ion shuttling with
individually-addressed single qubit rotations and detection,
high fidelity same- and mixed-species two qubit gates, and
real-time conditional operations, thereby demonstrating a
substantial fraction of the building blocks necessary for
scaling trapped-ion quantum information processors.
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报告题目:超低损耗与高损伤阈值激光薄膜研究
报告人:王占山 教授(同济大学精密光学工程技术研究所)
时间:2019年1月29日(周二)上午10:00
地点:光电所二层报告厅
摘要:
超低损耗、低热噪声激光薄膜是激光测量系统的核心元件,如何从光学损耗、热噪声两方面控制激光薄膜性能是当前精密测量和薄膜光学领域的热点和难点。同济大学建立了集超低损耗激光薄膜设计、制备、表征于一体的研究平台,对薄膜的吸收、散射、透射损耗的物理机制与控制技术开展了深入研究,实现了吸收<2ppm,散射~5ppm,反射率~99.999%的超低损耗激光薄膜。构建了光学薄膜热噪声的理论模拟和优化方法,研究了掺杂薄膜机械损耗的变化规律,对光学薄膜机械损耗进行了精确表征。相关研究推动了我国超低损耗、低热噪声激光薄膜的发展,将为精密测量领域的发展提供关键技术支撑。同时,我们还建立了全流程定量化高损伤阈值激光薄膜研制体系,实现了激光薄膜制备的稳定性和重复性,已在神光系列激光系统与激光武器上得到了广泛应用。
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报告题目:Propagating surface plasmons on metal nanowires and
their interaction with excitons in quantum dots
报告人:魏红 研究员(中科院物理所)
时间:2019.1.11(周五)上午11:00
地点:光电所二层报告厅
简介:魏红,中国科学院物理研究所研究员,博士生导师。2004年毕业于山东大学物理学院,获学士学位,2009年毕业于中国科学院物理研究所,获博士学位。2011年入选中国科学院青年创新促进会;2012年荣获中国科学院物理研究所科技新人奖;2013年荣获中国科学院卢嘉锡青年人才奖;2014年入选中国科学院卓越青年科家项目,获基金委优秀青年科学基金项目资助,入选北京市科技新星计划;2016年荣获第九届饶毓泰基础光学奖。
从事纳米光学和等离激元光子学的研究,主要工作集中于表面等离激元在纳米波导及其网络中的传播特性、纳米光学器件、表面增强光谱、等离激元-激子相互作用等。在Nano
Letters、Nature
Communications、PNAS等杂志发表论文40余篇,被SCI杂志引用2000余次,被邀请在重要国际学术会议上作邀请报告20余次。担任英国物理学会(IOP)出版社的Journal
of Optics编委,担任美国光学学会(OSA)出版社的Journal of the Optical Society
of America B的Topical Editor。
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报告题目:Integrated
quantum photonics in silicon
报告人:王剑威 研究员 (北京大学)
时间:2019.1.10(周四)下午4:30
地点:光电所二层报告厅
摘要:On-chip producing, controlling and detecting quantum
states of light with large-scale silicon-photonic circuits
opens the way to realizing complex quantum technologies for
applications in the fields of computing, simulation and
communication [1]. In this talk we present recent progress
on large-scale silicon-photonic quantum technologies and
applications, and discuss routes towards complex quantum
information processing with photons. We reported a
silicon-photonic device integrating around 550 components,
able to generate, manipulate and measure high dimensional
entanglement with high controllability and universality [2].
Universal two-qubit operations have been enabled recently by
controlling a complex network of linear-optic devices [3]. A
chip-to-chip quantum interconnect technology, allowing
entanglement distribution and teleportation between
separated chips, has been demonstrated going beyond a
single-chip quantum system [4]. With the developed quantum
photonic hardware it allows us to benchmark the simulation
and characterizations of electron spin systems [5] and
molecular systems with photons [6,7]. These results show
silicon-integrated quantum photonic circuits as a versatile
testbed for new quantum algorithms and as a route towards
large-scale quantum information processing, pointing the way
to applications in fundamental science and quantum
technologies.
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报告题目:Quantum
simulation of open systems with optically-trapped ultracold
atoms
报告人:罗乐 教授(中山大学)
时间:2019.1.9(周三)下午5:00
地点:光电所二层报告厅
摘要:Optically-trapped ultracold atoms have exhibit
extraordinary ability to simulate the dynamics of closed
quantum systems. But its potential as a simulator of open
quantum systems has yet to be explored. Here we studied open
quantum systems with balanced loss and gain which exhibit a
transition which engenders modes that exponentially decay or
grow with time and thus spontaneously breaks the parity-time
(PT) symmetry.Such PT -symmetry breaking transitions have
attracted many interests because of its extraordinary
behaviors and functionalities absent in the closed systems.
We have observed PT -symmetry breaking transitions by
engineering time-periodic dissipation and coupling, which
are realized through state-dependent atom loss in an optical
dipole trap of ultracold 6Li atoms [1]. Comparing with a
single transition appears for static dissipation, we find
that the time-periodic counterpart undergoes PT -symmetry
breaking and restoring transitions at vanishingly small
dissipation strength in both single and multiphoton
transitions domains, revealing rich Floquet phase structures
and topological phenomena associated to time-periodic
modulation.
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报告题目:Effects
of quantum interference in microcavity polariton condensate
报告人:薛艳 副教授(吉林大学)
时间:2018.12.28(周五)下午4:30
地点:光电所二层报告厅
摘要:Exciton polaritons in semiconductor microcavity
constitute the archetypal system to investigate condensate
in solid state materials with room temperature. Together
with the consideration of microscale size and large
nonlinearity, polariton condensate appears promising for
polaritonic devices for all-optical information and
communication processing. In this talk, I will first
introduce some concepts and progress in the study about
quantum interference in polariton condensate. Then I will
introduce how to use quantum interference respectively in
the spatial domain and in the temporal domain to study some
issues such as the stability of dark polariton soliton and
the polariton memory.
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报告题目:纳米光学和等离激元光子学基本问题研究
报告人:徐红星 院士(武汉大学)
时间:2018.12.26(周三)下午4:00
地点:光电所二层报告厅
简介:徐红星,中国科学院院士,武汉大学物理科学与技术学院教授,院长。长期从事表面增强光谱和等离激元光子学(plasmonics)方面的研究工作,在单分子表面增强光谱和纳米全光网络方面做出了开创性和系统性的工作。2010
获第十一届中国青年科技奖、2013 年获中国物理学会饶毓泰物理奖。在包括Nature Commun.,PRL,Nano
Lett.,PNAS,JACS, Adv.
Mater.等的国际著名科学杂志发表论文150余篇,其中影响因子>7的有42篇(其中30篇为第一或通讯作者)。全部论文近五年被SCI
杂志引用7000 余次,H
因子40,17篇论文被SCI杂志引用超过百次,最高单篇被引用1240余次,是1999年发表的所有PRL中引用最高的十篇文献之一,次高910余次,是2000年发表的所有PRE中引用最高的文献。在等离激元光子学领域最有影响力的四个国际会议(SPP,
NFO, SPIE 的Plasmonics
分会,等离激元光子学前沿国际会议FOP)中,担任前三个会议的程序委员会委员和FOP 会议的三届大会主席,其中FOP2
被Nature Photonics 专栏报道。
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报告题目:Fermion-Mediated Interactions Between Bosonic Atoms
报告人:Prof. Cheng Chin (The University of Chicago)
时间:2018.12.24(周一)下午4:30
地点:光电所二层报告厅
摘要:In
high energy and condensed matter physics, particle exchange
plays an essential role in the understanding of long-range
interactions. For example, the exchange of massive bosons
leads to the Yukawa potential. Phonon exchange between
electrons gives rise to Cooper pairing in superconductors.
When a Bose-Einstein condensate (BEC) of Cs is embedded in a
degenerate Fermi gas of Li, we show that interspecies
interactions can give rise to an effective trapping
potential, damping, and attractive boson-boson interactions
mediated by fermions. The latter, related to the
Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism, results from
a coherent three-body scattering process. Such mediated
interactions are expected to form novel magnetic phases and
supersolids. We show that for suitable conditions, the
mediated interactions can convert a stable BEC into a train
of "Bose-Fermi solitons".
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报告题目:Quantum optics with strongly interacting atomic systems
报告人:李霖 教授 ( 华中科技大学 )
时间:2018年11月10日(周六)上午10:00
地点:光电所二层报告厅
摘要:Manipulation of light at the single quanta level is an
essential goal in quantum optics, due to its importance for
quantum communications/computations and testing of
fundamental quantum mechanics. However, performing such
quantum operations on photons in a deterministic way turns
out to be extremely hard, as photons usually don’t interact
with each other. Here we present some of the recent
experiments where atomic systems are used to mediate the
interaction between photons. By coupling light with
high-lying Rydberg atoms or Cavity QED systems, atom-photon
and photon-photon interactions can be effectively
engineered. We demonstrate the on-demand generation of
non-classical light states and light-atom entanglement with
these systems.
简介:Lin's
research focus on quantum information and quantum optics
with Rydberg atoms and cavity QED. Lin started his Ph.D. in
Prof. Kuzmich’s group at Georgia Institute of Technology in
2010, working on long-lived quantum memory and
strongly-interacting Rydberg atoms. After moved to
University of Michigan in 2014, Lin setup a new experiment
single-handedly and investigated single-photon Rydberg
excitations. From 2017 to 2018, Lin worked in Prof. Gerhard
Rempe's lab at Max-Planck-Institute for Quantum Optics as a
posdoc, studied the realization of Schrödinger's cat with
cavity QED system. Lin joined Huazhong University of Science
and Technology as a professor in Aug. 2018 and is currently
setting up his cold atoms experiments.
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报告题目:人工微结构光场调控物理及应用
报告人:陈树琪 教授(南开大学物理科学学院)
时间:2018年11月7日(周三)下午5:00
地点:光电所二层报告厅
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报告题目:激光相干结构调控研究
报告人:蔡阳健 教授(山东师范大学物理与电子科学学院)
时间:2018年11月7日(周三)下午4:00
地点:光电所二层报告厅
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报告题目:基于悬浮光力学的量子模拟和量子时间晶体
报告人:尹璋琦 助理研究员(清华大学)
时间:2018年11月1日(周四)下午4:30
地点:光电所二层报告厅
摘要:
光悬浮的纳米系统具备超高的品质因子,可用于宏观量子叠加态的制备以及精密测量。在这里,我们讨论光悬浮包含氮-空位中心的纳米金刚石系统,在磁场下诱导出色心电子自旋与机械模式如质心运动或摆动模式之间的强耦合,进而制备其量子叠加态和实现多个色心间的有效耦合,模拟有限尺度的Lipkin-Meshkov-Glick
(LMG)
模型。接下来,我们简要的介绍时间晶体的概念,并发现有限尺度的LMG模型基态附近能出现有效的量子时间晶体和时间准晶体现象。
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报告题目:Low-noise lasers and amplifiers for microwave photonics
and metrology applications
报告人:Prof. Fabien Bretenaker(CNRS & ENS Paris-Saclay, France)
时间:2018年10月29日(周一)下午4:30
地点:光电所二层报告厅
简介:Fabien
Bretenaker graduated from Ecole Polytechnique, France, in
1988. He received his PhD degree from University of Rennes,
Rennes, France, in 1992 while working on ring laser
gyroscopes for Sagem. He joined the Centre National de la
Recherche Scientifique, Rennes, in 1994 and worked in Rennes
until 2002 on laser physics and nonlinear optics. In 2003,
he joined the Laboratoire Aimé Cotton, Orsay, France,
working on nonlinear optics, laser physics, quantum optics,
and microwave photonics. He is also a part time professor in
Ecole Polytechnique, Palaiseau, France, and adjunct
professor in Ecole Normale Supérieure Paris Saclay, Cachan,
France and in Raman Research Institute in Bangalore, India.
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报告题目:Quantum thermalization in frozen Rydberg gases
报告人:Prof. Pierre Pillet(CNRS & ENS Paris-Saclay, France)
时间:2018年10月29日(周一)下午3:30
地点:光电所二层报告厅
简介:Pierre
Pillet graduated from the Ecole Normale Supérieure
(1973-1977), where he obtained his PhD degree (Thèse de
troisième cycle) and the “Agrégation of Physics” both in
1977. In 1977 he joined the Centre National de la Recherche
Scientifique, and worked at Laboratoire Aimé Cotton. In 1982
he got his “Thèse d’Etat” in Physical Sciences (Tenure) at
University Paris-Sud. In 1982-1983 he joined the Stanford
Research Institute (SRI International) at Menlo Park
(California). He is today Director of Research (Exceptional
class) in CNRS. He has headed the Laboratoire Aimé Cotton
from 2001 to 2011, then he has headed the Laboratory of
Excellence “Physics Atom Light Matter” (LabEx PALM of
University Paris-Saclay) from 2011 to 2015. He has been
Professor (part time) at Ecole Polytechnique from 1992 to
2006. Pierre Pillet is recognized for his pioneering works
and developments in cold molecules and in cold Rydberg
atoms.
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报告题目:Magnetometry with NV color centers in diamond:
Application to nanophysics and high-pressure physics
报告人:Prof. Jean-François ROCH(ENS Paris-Saclay, France)
时间:2018年10月29日(周一)下午2:30
地点:光电所二层报告厅
简介:Jean-François Roch graduated in physics from the Ecole
normale supérieure de Cachan and the University of
Paris-Sud, with a PhD on quantum nondemolition measurements
that he realized at the Institut d’Optique in Orsay
(France). He was appointed in 1992 researcher at the CNRS.
He continued his quantum optics work at the Institut
d’Optique and then moved to the Ecole Normale Supérieure in
Paris to join the group of the Physics Nobel Prize Serge
Haroche where he investigated quantum effects associated to
whispering gallery modes.
In 1998, he became professor in physics at the
Ecole Normale Supérieure de Cachan in 1998 which now became
the ENS Paris-Saclay. There he started a research group on
the quantum properties of single light emitters. For the
past years, his research has been devoted to the application
of single point defects in diamond as quantum sensors. After
being the vice-rector of ENS Paris-Saclay in charge of
research and innovation activities (2009-2011), he settled a
joint research structure with the company Thales Research &
Technology which aims to develop quantum sensing techniques
and microwave photonics.
Jean-François Roch is co-author of 135
publications, with 2 publications in Science. His current
h-index is 41 (Web of Science).
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报告题目:10dB vacuum noise squeezing at 1064 nm in Taiwan
报告人:Prof. Ray-Kuang Lee(Institute of Photonics Technologies,
National Tsing Hua University, Taiwan)
时间:2018年10月22日(周一)下午5:00
地点:光电所二层报告厅
摘要:In this talk, I will report our recent implementation of
squeezed vacuum states at 1064 nm. With a bow-tie, optical
parametric oscillator (OPO) cavity, and our home-made
balanced homodyne detectors, noise reduction up to 10dB
below the vacuum is measured. Applications of our squeezer
to the gravitational wave detection will be discussed, with
the collaboration with Japanese KAGRA project. At the same
time, based on the niche of silicon photonics technologies
and semiconductor industries in Taiwan, we will also
introduce our proposal toward the implementation of scalable
quantum photonic chips by integrating photonic qubits
(single photon source, entangled photon pair, squeezed
light), optical components based on silicon photonics, and
photon detector arrays (single photon avalanche diode,
homodyne detector).
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报告题目:有机光伏材料中的超快光电过程
报告人:张春峰 教授(南京大学)
时间:2018年10月11日(周四)下午5:00
地点:光电所二层报告厅
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报告题目:半导体胶体纳米晶的单粒子光学特性研究
报告人:王晓勇 教授(南京大学)
时间:2018年10月11日(周四)下午4:00
地点:光电所二层报告厅
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报告题目:基于原子系统的量子存储
报告人:史保森 教授(中国科学技术大学)
时间:2018年8月21日(周二)下午4:30
地点:光电所二层报告厅
摘要:
长距离量子通信和可扩展线性量子计算的实现离不开量子存储器。量子存储器是一个能够按照需要存储和读出量子态的系统。如果量子态的制备或操控通过处于可见或近红外波段的光子实现,则这个量子存储器通常被称为光量子存储器。一个光量子存储器必须能够存储各种非经典态,比如单光子态、纠缠态或压缩态等。评价一个量子存储器性能有存储保真度、存储效率、存储时间、存储带宽及多模存储能力等诸多指标。
量子存储器的实现离不开存储介质,一个理想的存储介质应该具备较大的光学厚度和较长的消相干时间。冷原子系综中原子密度较大,因而具有较大的光学厚度,且由于原子温度低、运动速度小,由原子之间的碰撞和原子扩散引起的消相干效应弱,因而基于冷原子的量子存储器具有高效率、高保真度、长存储时间等优点,一直是量子存储研究的热点领域。量子存储的实现需要合适的存储方案。目前用于量子存储的方案多种多样,其中基于电磁诱导透明(EIT)和远失谐双光子跃迁方案
(Raman)是两种广泛应用的存储协议。
量子存储的发展深刻影响着量子信息的发展,人们对于量子存储的要求随着不同的量子信息任务发生了很大的变化。未来的量子存储研究需要考虑到波长可调、频率和空间多模复用的功能,同时还要考虑到非经典光源的不同波长和带宽的兼容性问题,因此构建一个多功能量子存储器是量子信息实用化的一个关键问题。近年来我们小组紧紧围绕多功能量子存储器的实现及相关技术的突破这一核心目标开展了系统的实验研究,取得了系列进展。本报告将介绍我们小组在基于原子气体实现量子存储及相关方面的研究成果,主要内容包括单光子态和qubit态、偏振纠缠和轨道角动量纠缠、二维和高维纠缠的量子存储,以及相关的非经典光场的产生、量子接口的实现等。
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报告题目:Dynamics of dual Bose Fermi superfluids
报告人: Prof. Christophe Salomon(Laboratoire Kastler Brossel,
Ecole Normale Supérieure, Paris, France.)
时间:2018年8月20日(周一)下午4:30
地点:光电所二层报告厅
摘要:Using dilute lithium quantum gases where interactions can
be tuned, we have produced a Bose-Fermi mixture where both
species are superfluid. Such a mixture had long been sought
in liquid helium where superfluidity was only achieved
separately in bosonic 4He and fermionic 3He. By exciting
center of mass oscillations of the mixture we probe the
superfluid counterflow which exhibits very small damping
below a certain critical velocity. We compare this
surprisingly high critical velocity to a recent theoretical
prediction. Finally we show that the lifetime of the
Bose-Fermi mixture is governed by a very simple formula
involving the fermionic two-body contact introduced by S.
Tan.
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报告题目:Quantum simulation of Hawking-Unruh radiation
报告人:金政 教授(美国芝加哥大学)
时间:2018年8月17日(周五)下午4:30
地点:光电所二层报告厅
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报告题目:Floquet physics: entering a new exotic quantum world
报告人:金政 教授(美国芝加哥大学)
时间:2018年8月17日(周五)上午10:00
地点:光电所二层报告厅
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报告题目:From in situ imaging at 1 μm to super resolution
imaging at 1 nm
报告人:金政 教授(美国芝加哥大学)
时间:2018年8月16日(周四)晚上8:00
地点:光电所二层报告厅
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报告题目:铁电晶体中的畴与畴工程
Domain and domain engineering in ferroelectric crystals
报告人:祝世宁 中国科学院院士(南京大学)
时间:2018年8月16日(周四)下午5:00
地点:光电所二层报告厅
摘要:Engineering domain in ferroelectric crystals has become a
very active field involving many important applications in
linear optics, nonlinear optics, laser and quantum optics.
At its early stage, the researches were focused on
quasi-phase-matched second-harmonic-generation from the
periodically poled ferroelectric crystals. The research
later was extended to many other nonlinear optical
processes, such as optical parametric generation or
oscillation, third-harmonic-generation, nonlinear light
scattering, nonlinear Cherenkov radiation, nonlinear Talbot
effect etc., in which phase matching was fulfilled by either
quasi-phase-matching or nonlinear Huggens-Fresnel principle.
Nowadays, the study of domain engineering enters a new
regime, in which,the goal is to generate and control photons
at will. The bright entangled photons have been generated in
such crystals by spontaneously parametric downconversion,
and been further controlled with full freedom offered by
engineered domain, such as focusing, beam-splitting etc.
This will bring revolutionary impacts on quantum optics and
information in future.
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报告题目:量子卫星的任务和空间光电探测技术
报告人:王建宇 中国科学院院士(中科院上海技术物理研究所)
时间:2018年8月16日(周四)下午3:30
地点:光电所二层报告厅
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报告题目:High-Q micro-disk cavities and their applications
报告人:肖敏 教授 (南京大学,美国阿肯色大学)
时间:2018年7月26日(周四)下午4:00
地点:光电所二层报告厅
摘要:The whispering gallery modes of micro-disk cavities can
have very high quality (Q) factors and small mode volumes.
Such high-Q micro-disk cavities have been widely used for
ultra-sensitive biosensors, low-threshold and narrow
linewidth lasers, cavity-QED studies, frequency comb, and
cavity opto-mechanics applications.
When two or more high-Q
micro-cavities are coupled together, interesting mode
splitting effects occur. With precisely controlled coupling
between two micro-disk cavities, EIT (electromagnetically
induced transparency)-like phenomenon can be observed and
carefully studied. More interestingly, when one of the
micro-toroid cavities has a gain that balances the loss in
the other micro-cavity, the novel effect of parity-time (PT)
symmetry appears in this system. By making use of the gain
saturation nonlinearity in the active micro-cavity,
nonreciprocal light transmission can be achieved in various
micro-cavity systems. Also, with the help of directional
nonlinear parametric amplification process in the
micro-cavity, true optical isolation can be achieved.
In this talk, I will present some of
our experimental works on demonstrating micro-cavity lasers,
coupled micro-disk cavities, parity-time symmetric effects,
and optical isolation.
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报告题目:倾斜扫描激光显微镜(Oblique Scanning Laser
Microscopy):一种大视场三维多模态成像的新方法
报告人:易季 教授(美国波士顿大学)
时间:2018年7月25日(周三)下午4:00
地点:光电所二层报告厅
摘要:生命科学的进步离不开新的光学成像方法。在一方面有分子成像技术:
比如利用特异的荧光蛋白分子标定或者是利用分子本身的光学特性,共聚焦显微镜可以达到三维亚细胞的分辨率对特定分子的三维空间以及动态成像。此类技术的特异性优点也有自身的缺点:除了特定的分子外,其他的结构是看不到的。在另一方面,一些结构成像的方法,例如光学相干断层成像(optical
coherence
tomography),可以对所有的结构成像,然而他们却缺乏了分子特异性。因此,多模态的成像方式就显得很重要,可以将分子成像和结构成像结合在一起。在这个方面,大视场三维多模态成像是一个很具挑战的领域。为此,我们实验室开发了一种新的倾斜扫描激光显微镜技术,可以完美的将分子成像和结构成像融合在一起,实现无需深度扫描就可以达到的三维多模态成像功能。在这个报告里,我们会简单的介绍一下这个技术,和我们最新的视网膜三维多模态成像的应用。
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报告题目:A phonon laser operating at the exceptional point
报告人:张靖 教授 (清华大学)
时间:2018.7.18(周三)下午4:00
地点:光电所二层报告厅
摘要:Non-Hermitian physical systems have attracted
considerable attention lately for their unconventional
behaviour around exceptional points (EPs). In particular,
many novel EP-related concepts such as unidirectional lasing
and invisibility and chiral transmission have been realized.
Given the progress in understanding the physics of EPs in
various photonic structures, it is surprising that one of
the oldest theoretical predictions associated with them,
i.e., a dramatic broadening of the laser linewidth, has
remained out of reach of experiments so far. Here, we fill
this gap by steering a phonon laser through an EP in a
compound optomechanical system formed by two coupled
resonators. We observe a pronounced linewidth broadening of
the mechanical lasing mode generated in one of the
resonators when the system approaches the EP. This is the
first time, to our knowledge, that the linewidth broadening
of a laser at an EP is explicitly demonstrated.
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报告题目:Environment-Assisted Speed-up Evolution in Cavity
Quantum Electrodynamics
报告人:Prof. Luis A. Orozco(JQI, University of Maryland and
NIST)
时间:2018.7.5(周四)下午5:00
地点:光电所二层报告厅
摘要:Cavity quantum electrodynamics (CQED) is an open quantum
system with dynamics that lends to detailed studies. We
measure the quantum velocity of the evolution of the
electric field state in a weakly excited CQED system. The
system consists of a single mode of an optical cavity and a
collection of atoms. Our experiment operates in the
intermediate regime of the CQED where the atom
dipole-coupling rate to the single mode of the cavity is
comparable to the decay rate of the cavity and the atomic
spontaneous emission rate.
We consider the mode of the electromagnetic field as the
quantum system of interest, with a preferential coupling to
a tunable environment: the atoms. By changing the number of
atoms coupled to the optical cavity mode, we accelerate the
speed to reach the steady state: the quantum speed of the
repopulation of state in the optical cavity increases with
the coupling between the mode of optical cavity and this
non-Markovian reservoir (the number of atoms). We find a
non-linear relationship between quantum velocity and the
number of atoms in the system.
This talk will introduce the platform and the quantum
correlations to characterize it, and then show both the
theory and the experiment.
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报告题目:Tradeoffs in Quantum Steering
报告人:程书明 博士(澳大利亚 griffith university)
时间:2018.6.14(周四)下午5:00
地点:光电所二层报告厅
摘要:Quantum steering was introduced by Schrodinger, in
response to the famous paradox raised by Einstein, Podolsky,
and Rosen (EPR) in 1935. It describes the conditioning
effect between two parties, Alice and Bob say, that Bob's
system could be remotely prepared into different states by
different choices of Alice's measurements when they share a
pure bipartite non-product state. In this talk, I will talk
about the quantum steering for two-qubit states and beyond
qubits. In particular, the following issues are examined: 1)
Which states Bob's qubit can be steered to by Alice's qubit
(qudit)? 2) What is the connection between this set of
steered states and the degree of quantum correlation? 3)
Which convex decomposition of Bob's local state can be
steered to by Alice's qubit (qudit)? 4) And for a
multi-party state, are there restrictions on the degree to
which one party can steer the systems of all other parties?
I will mainly use the quantum steering ellipsoid to tackle
these problems and report monogamy relations of quantum
steering ellipsoids for qubits systems and beyond qubits.
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报告题目:Phase Transition of Atomic System in An Optical Lattice
报告人:周小计 教授 (北京大学)
时间:2018年6月9日(周六)上午10:00
地点:光电所二层报告厅
摘要:Atomic many-body phase transitions and quantum
criticality have recently attracted much attention in an
optical lattice. In this talk, first I report an observation
of a dynamical sliding-phase superfluid that emerges in a
nonequilibrium setting from the quantum dynamics of a
three-dimensional ultracold atomic gas loaded into the
P-band of a one-dimensional optical lattice. A shortcut
loading method is used to transfer atoms into the P-band at
zero quasi-momentum within a very short time duration. The
system can be viewed as a series of “pancake”-shaped atomic
samples. For this far-out-of-equilibrium system, we find an
intermediate time window with lifetime around tens of
milliseconds, where the atomic ensemble exhibits robust
superfluid phase coherence in the pancake directions, but no
coherence in the lattice direction, which implies a
dynamical sliding-phase superfluid.
Second, we perform an experimental
study of finite-temperature superfluid transition of bosonic
atoms confined in a three dimensional triangular lattice,
whose structure can be continuously deformed to dimensional
crossover regions including quasi-one and two dimensions.
This non-standard lattice system provides a versatile
platform to investigate many-body correlated phases. For the
three dimensional case, we find that the finite temperature
superfluid transition agrees quantitatively with the
Gutzwiller mean field theory prediction, whereas tuning
towards reduced dimensional cases, both quantum and thermal
fluctuation effects are more dramatic, and the experimental
measurement for the critical point becomes strongly deviated
from the mean field theory. We characterize the fluctuation
effects in the whole dimension crossover process. These
experiments potentially open up a novel venue to search for
quantum criticality and exotic dynamical phases in the
high-band excitations in optical lattices.
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报告题目:Photon detection with superconducting detectors from
millimeter-wave to gamma-ray
报告人:高湔松 研究员(美国NIST研究所)
时间:2018年6月8日(周五)上午10:30
地点:光电所二层报告厅
摘要:Operating at a temperature less than 1 Kevlin above
absolute zero, superconducting detectors provide ultimate
sensitivity for photon detection and cover an ultra-wide
wavelength range, from millimeter-wave, IR/visible/UV, to
x-ray and gamma-ray. They are used in the most demanding
applications such as the detection of cosmic-ray background
(CMB) signal and single infrared photons. The principle and
recent progress of several important superconducting
detector technologies will be presented. Examples of their
applications in quantum information processing and
astrophysics will be discussed.
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报告题目:量子磁强计高空间分辨率测量的探索与思考
报告人:董海峰
副教授(北京航空航天大学)
时间:2018.6.4(周一)下午5:00
地点:光电所二层报告厅
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报告题目:Dressing ultra-cold atoms for control and quantum
technology
报告人:Prof. Barry Garraway(Department of Physics and
Astronomy, University of Sussex, Falmer, Brighton, BN1 9QH,
United Kingdom)
时间:2018.6.2(周六)上午10:00
地点:光电所二层报告厅
摘要:Dressing atoms with radio-frequency and microwave
radiation opens up new possibilities for ultra-cold atoms
and a BEC in new types of trap and in new topologies
involving waveguides. This is because of the flexibility
inherent in the vector coupling of a magnetic dipole moment
to electromagnetic fields which can be varied in time,
frequency, orientation and space. This may in turn result in
quantum technology applications to sensing (with ring traps
and gyroscopes), metrology, interferometry and atomtronics.
In this talk we will introduce the concept of the dressed
atom, and present several designs for matter-wave ring
traps, as well as rf-dressed lattices for ultra-cold atoms
and a description of Landau-Zener losses from these traps.
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报告题目:钌氧化物Sr4Ru3O10中奇异磁特性的起源
报告人:杨继勇 副研究员(中国科学院强磁场科学中心)
时间:2018.5.10(周四)下午5:00
地点:光电所二层报告厅
摘要:4d钙钛矿关联电子体系Srn+1RunO3n+1 (n=1,
2,∞)中存在多种自由度,包括电荷、自旋、晶格以及轨道间的复杂相互作用,蕴含着丰富的物理现象,如p波超导电性(Sr2RuO4)和量子临界(Sr3Ru2O7)等。n=3的Sr4Ru3O10是一种具有奇异磁性质的材料。该材料在TC~105
K发生铁磁转变,随后在TM~50
K发生第二个磁转变。在TM以下,其磁性质具有很强的各项异性,当磁场沿c方向时,表现出典型的铁磁行为,而当磁场沿ab面时,却表现出类似于反铁磁的行为并存在磁场诱导的变磁转变。以前,对该材料所具有的这种奇异磁特性的机理一直缺乏很好的理解。近年来,我们通过机械解离的办法首次将Sr4Ru3O10单晶的厚度推进到纳米尺度,并通过输运测量系统的研究了不同厚度Sr4Ru3O10纳米薄片的磁特性。我们发现,Sr4Ru3O10中的第二个磁转变实际上是一种自旋重取向行为,与该材料中的自旋晶格耦合密切相关。
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报告题目:Electronic Phase Control with an Electric Field
报告人:袁洪涛 教授(南京大学现代工程与应用科学学院)
时间:2018.5.4(周五)下午5:00
地点:光电所二层报告厅
摘要:Electric-field control of charge carrier density has
attracted much attention since it is remarkably simple for
modulating physical properties of condensed matters and for
exploring new functionalities with a transistor
configuration. To realize novel field-effect modulated
electronic phenomena in solids, a broad range of attainable
carrier density is always required. However, so far, owing
to the limitation of dielectric breakdown in most solid
dielectrics, the maximum carrier density accumulated in
conventional field-effect transistors (FETs) is quite low
(<< 1013 cm-2) and thus seriously limits the tunability of
electronic states of solids, for example, not sufficient
enough to induce insulator-to-superconductor transition.
While, recently a new type of transistor, known as
electric-double-layer transistor (EDLT), with ionic liquids
(ILs) as gate dielectrics have been proved to be able to
effectively attain a high carrier density up to levels of
around 1015 cm-2 and to realize a large local electric field
up to 50mV/cm at liquid/solid interfaces, which are
attracting increasing interests because of their potential
to greatly tune electronic states and even to create novel
states of matter which are impossible or difficult to obtain
in conventional methods. In this presentation, I will
discuss the interfacial carrier accumulation within liquid
gated EDLTs and their novel tunability of varied electronic
phase transitions in oxides, chacogenides and Dirac
materials like graphene and topological insulators.
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报告题目:Two-dimensional artificial nano-hybrids and their
quantum properties
报告人:韩拯 教授(中科院金属研究所)
时间:2018.4.20(周五)下午5:00
地点:光电所二层报告厅
摘要:When different materials are interfaced/jointed with each
other, the resulted hybrid systems often manifest
fascinating physical properties that do not exist in nature.
Among the many artificial hybrids (sometimes addressed as
meta-materials or hetero-structures), nano-hybrid made with
low-dimensional materials and other functional materials is
attracting tremendous attentions in recent years.
In this talk, we will mainly go
through a couple of examples of our studies on the
graphene/superconducting-islands, and the 2D
materials/h-Boron-Nitride nano-hybrid systems. In the
former, the superconducting behavior is successfully coupled
to the gate-tunable feature of graphene, leading to a
metal-superconducting quantum phase transition at the ground
state.[1] While in the later, ultra-flat and ultra-clean
interface allow ballistic electronic transport, opening new
path to realize the paradigm of electron optics.[2] Our
recent experimental progresses on MoS2/h-BN
hetero-structures will also be discussed.[3] We expect that
artificial nano-hybrids and their quantum properties can be
expanded into many research areas that are important for
both fundamental studies and future applications.
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报告题目:Pure Gaussian states in open quantum systems
报告人:马山 讲师(中南大学信息学院)
时间:2018.4.19(周四)下午5:00
地点:光电所二层报告厅
摘要:Pure Gaussian states serve as key resources for
continuous-variable quantum information processing.
Therefore, preparation of pure Gaussian states is an
important task. One powerful approach is based on reservoir
engineering. That is, we engineer an open quantum system by
designing its coherent and dissipative processes such that
the system is strictly stable and evolves into a target pure
Gaussian state. In this talk, I will review recent results
on the preparation of pure Gaussian states via reservoir
engineering and some specific applications will also be
discussed.
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报告题目:Dynamical classification of topological quantum phases
报告人:刘雄军 教授 (北京大学,量子材料中心)
时间:2018.4.9(周一)下午5:00
地点:光电所二层报告厅
摘要:Topological phase of matter is now a mainstream of
research in condensed matter physics, of which the
classification, synthesis, and detection of topological
states have brought many excitements over the recent decade
while remain incomplete with ongoing challenges in both
theory and experiment. In this talk I present a universal
dynamical characterization of the topological quantum phases
classified by integers, which was proposed very recently in
our work. The framework of the present study consists of
basic theorems. First, we uncover that classifying a generic
d-dimensional (dD) gapped topological phase can reduce to a
(d-1)D invariant defined on so-called band inversion
surfaces (BISs), rendering a fundamental bulk-surface
duality. Further, we show in quenching across phase boundary
the (pseudo)spin dynamics to exhibit unique topological
patterns on BISs, which are attributed to the post-quench
bulk topology and manifest a dynamical bulk-surface
correspondence. The topological phase is then classified by
a dynamical topological invariant measured from dynamical
spin-texture field on the BISs. Applications to quenching
experiments on feasible models are proposed and studied. The
future interesting issues will be discussed.
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报告题目:纳米材料与器件的研发挑战及其技术变革
报告人:丁孙安 研究员(中科院苏州纳米所)
时间:2018.4.3(周二)下午4:00
地点:光电所二层报告厅
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报告题目:原子芯片上的超冷原子操控
报告人:李晓林 副研究员(中科院上海光机所,中科院量子光学重点实验室)
时间:2018.1.25(周四)下午4:00
地点:光电所二层报告厅
摘要:
原子芯片将原子光学元器件集成到一块半导体芯片上,可完成超冷原子的制备、探测和操纵,它把量子光学、物质波光学理论和微制造技术联系在一起,可简化实验装置,提供更紧的束缚和更小的磁阱尺寸,实现对被囚禁原子团进行复杂且精确的操纵,例如导引型陀螺仪、冷原子与表面相互作用、精密磁场成像、基于自复相的长相干时间获得等。我们在原子芯片上实现了铷原子BEC,并开展了导引、分束和系统小型化等方面的研究工作。利用原子芯片产生的准一维势阱,计划开展里德堡缀饰和自旋压缩方面的研究。
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报告题目:基于原子系综的多自由度存储与多体相变
报告人:丁冬生 博士、教授(中国科技大学,中科院量子信息重点实验室)
时间:2018年1月16日(星期二)下午5:00
地点:光电所二层报告厅
摘要:
利用光和冷原子系综相互作用,实现单光子和存储单元之间的混合纠缠以及存储单元之间的混合纠缠,对于构建混合自由度的量子网络具有重要意义。本报告中,主要讲解如何实现光子轨道角动量、偏振、路径等单个自由度纠缠的存储,以及多个自由度的混合纠缠,以及超纠缠的量子存储。实验结果证明,基于冷原子系综的量子存储器可以存储光子多个自由度,并高保真地保持量子特性。此外,还将介绍基于Rydberg原子的多体相变相关方面的研究进展。传统方法主要基于Rydberg原子的布居数来调控相变,报告人将介绍基于Rydberg原子的电磁诱导透明效应实现比传统方法更高精度的相变。实验中可以观测到一阶相变、二阶相变以及光学双稳现象、双稳操控等。
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报告题目:保护性测量与量子实在
报告人:高山 教授(山西大学科学技术哲学研究中心)
时间:2018年1月6日(周六)上午10:00
地点:光电所二层报告厅
摘要:
保护性测量(Protective
Measurements)的理论蕴含和实验实现是近年来量子力学基础研究中的一个热点。本报告将介绍保护性测量的概念的起源,基本原理,以及围绕它的关于波函数实在性的争论。此外,还将介绍报告人关于保护性测量意义的最新研究进展,尤其是检验波函数实在性的新的实验建议。
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报告题目:魔幻光强偶极阱与量子信息处理
报告人:何晓东 博士、副研究员(中国科学院武汉物理与数学研究所)
时间:2018年1月4日(周四)下午5:20
地点:光电所二层报告厅
摘要:
可控的中性原子阵列是用于实现量子计算机和量子模拟器的众多候选体系之一。相比于其他体系,中性原子阵列的优势在于其可扩展性,而单比特的独立控制与读出是它的劣势之一。最近,两个不同的研究组在2D和3D原子阵列中演示了保真度高于99%的单个原子比特的寻址操作,但保真度与容错量子计算阈值(99.99%)还有一定距离。为了达到并突破该阈值,我们利用最近发展的魔幻光强技术有效抑制单量子比特的退相干作用,实现了保真度高于99.99%的微波驱动的单量子比特逻辑门,这一研究结果为实现可扩展中性原子容错量子计算机打下了坚实的基础。
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报告题目:基于里德堡阻塞的异核双原子纠缠
报告人:许鹏 博士、副研究员 (中国科学院武汉物理与数学研究所)
时间:2018年1月4日(周四)下午4:20
地点:光电所二层报告厅
摘要:
操控不同粒子间的纠缠对于模拟和理解强关联的多体相互作用体系等有重要意义。我们在异核单原子囚禁的基础上,利用480nm和780nm激光将铷原子相干激发到主量子数n=79的里德堡态;利用铷-85和铷-87在光谱频率上的差别,在原子间距为3.8微米时依然实现了对单个原子的寻址及完备操控。相比同种原子体系,我们实现了更为优越的串扰抑制,更强的里德堡态原子间的偶极-偶极相互作用和更高效的里德堡阻塞。在此基础上我们首次实现了异核原子间的量子受控非门和量子纠缠,不仅展示了异核体系在寻址和抑制原子间操作串扰方面的优势,从而推进多组份原子的量子计算方案,而且为基于异核里德堡原子体系模拟复杂自旋相互作用模型铺平了道路。
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报告题目:Non-equilibrium dynamics of ultracold Bose gases in
optical lattices using a scanning electron microscope
报告人:Dr. Jian Jiang (TU Kaiserslautern)
时间:
2017年12月23日(周六)上午10:00
地点:光电所二层报告厅
摘要:
In this talk, I will first introduce our experimental
platform, a scanning electron microscope for ultracold
quantum gas, followed by a discussion of an experiment in
which we characterize the emerging steady-states of a
driven-dissipative Josephson junction array, realized with a
BEC in a onedimensional optical lattice. In this experiment,
by locally applying dissipation using the electron beam at
an initially full site, the superfluid response of the
respective site breaks down. This can be seen as an
extension of the paradigm of Coherent Perfect Absorption
(CPA). In its original occurrence CPA refers to the complete
extinction of bidirectional incoming radiation by spatially
localized absorber embedded in a waveguiding medium.
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报告题目:Strong atom-light interaction in nanophotonic
structures
报告人:栾兴生博士 (美国加州理工学院)
时间:
2017年12月20日(周三)下午5:00
地点:光电所二层报告厅
摘要:
In this talk, I will briefly review the physics and recent
advances towards strong atom-light interaction in
nanophotonic structures. In the first half, I will present
some recent results on trapping atoms near a photonic
crystal waveguide in Professor Jeff Kimble's group. By
studying the loading process into a nanophotonic trap, we
are now able to load >3 times more atoms into the
side-illumination trap above the nanophotonic waveguide
compared with previous published results. In the second
half, I will present our recent efforts towards trapping an
array of atoms deterministically, by integrating with
optical tweezers integrating optical tweezers with
nanophotonic waveguide system. We show that our system is a
promising toolbox to study exotic quantum many body physics.
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报告题目:高效量子精密测量
报告人:项国勇 教授 (中国科学技术大学)
时间:
2017年12月4日(周一)下午5:00
地点:光电所二层报告厅
摘要:
量子精密测量是伴随着量子信息技术的发展而发展起来的一个重要的研究领域。我们主要介绍如何实现超越经典标准量子极限的参数估计,包括量子相位估计,量子多参数估计,量子态的估计以及量子反馈控制在提高估计精度中的应用。
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报告题目:利用原子纠缠超越测量精度的经典极限
报告人:尤力 教授(清华大学)
时间:
2017年11月30日 (周四)下午5:00
地点:光电所二层报告厅
摘要:
关于测量的科学对人类至关重要。测量的精度决定了我们对自然的认知程度和相关自然规律的准确度。现行的精密测量通常基于单个物理系统或者它的多份拷贝,其测量精度受限于经典极限。建立多个相同体系之间的量子纠缠可以超越测量精度的经典极限。本报告将介绍一些基于原子物理系统的相关研究工作。
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报告题目:Reflecting on an alternative (parity-time-symmetric)
quantum theory and its analog in optics
报告人:Prof.Ray-Kuang Lee高效量子精密测量(Institute
of Photonics Technologies,
National Tsing-Hua University,Taiwan)
时间:
2017年11月14日(星期二)下午5:00
地点:光电所二层报告厅
摘要:
By no-signaling principle, we showed that parity-time (PT)-
symmetric quantum theory as an extension of the quantum
theory to non-Hermitian Hamiltonians is either a trivial
extension or likely false as a fundamental theory. In
addition to the implementation PT-symmetric optical systems
by carefully and actively controlling the gain and loss, we
show that a 2 × 2 PT-symmetric Hamiltonian has a unitarily
equivalent representation without complex optical potentials
in the resulting optical coupler. Through the Naimark
dilation in operator algebra, passive PT-symmetric couplers
can thus be implemented with a refractive index of real
values and asymmetric coupling coefficients. Moreover, with
a phase-space representation on the vicinity of an
exceptional point, we show that a PT-symmetric phase
transition from an unbroken PT-symmetry phase to a broken
one is a second-order phase transition.
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报告题目:腔光力学与宏观机械振子的基态冷却及耦合调控
报告人:刘永椿 助理教授(清华大学)
时间:
2017年10月27日(星期五)下午5:00
地点:光电所二层报告厅
摘要:
光学微腔与机械振子的耦合所形成的腔光力系统可以为宏观机械振子的量子操控提供技术手段,从而将量子物理的研究拓展到宏观尺度。这使得人们能够定量地研究量子-经典边界,以及为量子精密测量和量子信息处理提供新的工具。本报告将介绍报告人在机械振子的基态冷却以及腔光力耦合调控方面的工作。首先,将机械振子冷却到量子基态是对其进行量子操控的先决条件,我们用非微扰方法建立了腔光力冷却动力学过程的统一理论框架,提出动态耗散冷却方案,显著降低强耦合区的冷却极限;提出耦合腔冷却方案,突破边带可分辨条件的限制。另外,腔光力系统中的强耦合是量子相干操控的必要条件,同时也是实验实现的难点,我们提出了频率匹配共振增强和复合微腔方案实现对耦合的有效调控,为耦合增强提供了新的实现手段。
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报告题目:混沌光通信应用研究
报告人:义理林 教授(上海交通大学)
时间:
9月23日 上午10:00
地点:光电所二层报告厅
摘要:混沌光通信经过二十多年的研究,取得了长足的进展,目前已经实现10Gb/s信号传输100公里的城域网现网演示。但混沌光通信的进一步发展受到很多现实的制约。本报告主要介绍混沌光通信走向应用的技术障碍,以及解决这些障碍的技术途径。
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报告题目: Listening to space time vibrations
报告人:Prof. Jerome Degallaix(Laboratoire des Matériaux Avancés
(LMA) CNRS– Lyon, France.)
时间:
2017.7.21 下午5:00
地点:光电所二层报告厅
摘要:The recent announcements of the discovery of
gravitational waves from the coalescence of two binary black
holes has opened a new window to study the universe. The
measurement of those extremely small perturbations of space
time has only been possible thanks to the technological
progress happening in the last two decades.In this
presentation, we will come back to the astrophysical
discoveries but the focus will be on the detector itself, a
giant Michelson interferometer with state of the art large
optics. Finally at the end of the talk, we will discuss the
future projects in the field.
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报告题目: Quantum information with neutral atoms and Rydberg
interactions
报告人:M. Saffman (University of Wisconsin-Madison)
时间:2017年7月15日 上午10点
地点:光电所二层报告厅
摘要:Rydberg interactions are now in use in many research
groups for quantum information processing. I will present
experiments showing the creation of entangled |W> states of
~10 atoms, and two-atom Bell states. While these experiments
form a basis for future developments, scalable quantum
computing will require improvement of many aspects of these
experiments. I will address recent ideas and progress in
several directions including doubly magic trapping for long
coherence qubits,higher gate fidelity with shaped analytic
pulses, and measurement free error correction, which
leverages the potential of Rydberg interactions for
efficient multi-qubit gates.
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报告题目: Magnetic solitons in a binary Bose-Einstein condensate
报告人:Chunlei Qu (BEC Center, University of Trento, Italy)
时间:2017.6.5(周一)上午11:00
地点:光电所二层报告厅
摘要:Since the first experimental realization of Bose-Einstein
condensation (BEC) in 1995, many intriguing physics have
been observed with ultracold atomic gases. For instance,
solitons, the fascinating topological excitations of
nonlinear systems that can move in their medium without
losing their shape, have been engineered in BEC. I will talk
about our recent results on the investigation of a new type
of soliton, magnetic soliton, in a binary BEC. In the
absence and in the presence of a coherent coupling between
the two components, the magnetic soliton solutions exhibit
interesting distinct features . I will also briefly discuss
our recent experimental observation of the spin-dipole
oscillation and polarizability of a binary condensate .
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报告题目: Microcavity Nonlinear Photonics
报告人:邹长铃 副研究员(中国科学技术大学)
时间:2017.5.25(周四)下午5:00
地点:光电所二层报告厅
摘要:The optical microcavities provide an excellent platform
for strong light-matter interactions, due to their ultrahigh
quality factor and small mode volume. The microcavities have
been used for high sensitive sensing, low threshold lasing
as well as single photon quantum gates by interacting with
single emitters. Here, we explore the nonlinear optical
processes in microcavities. By carefully engineering the
geometry of microcavities, we demonstrated the coherent
frequency conversion, narrow linewidth photon pair source,
high efficient second harmonic generation, third harmonic
generation, as well as frequency comb. These integrated
nonlinear photonic devices, which are robust, compact and
scalable, hold the great potential for future applications.
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报告题目: Optimal experimental test of macroscopic realism
报告人:薛鹏 教授 (东南大学)
时间:5月13日(周六)上午10:00
地点:光电所二层报告厅
摘要:Macrorealism,
as defined by Leggett and Garg, posits that a macroscopic
system always exists in a well-defined state and that it can
be measured without disturbing it. From these assumptions
follow a set of inequalities, the Leggett-Garg inequalities,
which hold under macrorealism but can be violated by quantum
mechanics. The degree to which quantum systems can violate
these inequalities is bounded and, in particular, if the
measurements on the system are genuinely dichotomic, the
bound for these temporal inequalities is the same as the
Tsirelson bound of the corresponding spatial Bell
inequality. We realise a photonic Leggett-Garg test on a
three-level system and implement measurements that admit
three distinct measurement outcomes, rather than the usual
two. In this way we obtain violations of a Leggett-Garg
inequality significantly in excess of the Tsirelson bound.
This underlines the difference between Bell and Leggett-Garg
inequalities and hence spatial and temporal correlations in
quantum mechanics. We also report violations of a second
consequence of macrorealism, the quantum-witness equality,
up to the maximum permitted for a three-outcome measurement.
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报告题目: From Superradiance Lattice to Topological Quantum
Optics
报告人:Dawei Wang Department of Physics and Astronomy, Texas
A&M University
时间:2017年5月11日 下午5:00
地点:光电所二层报告厅
摘要:Superradiance
has grown into a major topic in quantum optics since Dicke’s
seminal paper in 1954. Recently, timed Dicke states, the
collective excitations of extended atomic ensembles by
single photon absorption, have been found with interesting
properties such as directional emissions and collective Lamb
shifts. By combining the timed Dicke states with the
electromagenetically induced transparency, we can construct
a momentum-space tight-binding lattice, coined the
superradiance lattice [1], which has been recently realized
in BEC by Jing Zhang's group from Shanxi University. In this
talk, I will introduce the basic concept of the
superradiance lattice and its applications in quantum
metrology [2] and optical diodes [3]. In particular, the
Haldane model can be simulated in two dimensional
superradiance lattices [4]. The same physics can be extended
to a cavity QED system, simply a two-level system coupled
with three cavities, where the chiral edge currents in a
Fock-state lattices enables the preparation of Schrodinger
cat states [5]. This study shows that the physics of
topological insulators can be demonstrated in quantum optics
systems and have important applications.
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报告题目:Development of high power femtosecond laser source and
various kinds of UV and VUV laser generation
报告人:赵智刚 博士(东京大学 物性研究所)
时间:2017年4月5日 下午5:00
地点:光电所二层报告厅
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报告题目:单频光纤激光技术与器件
报告人:徐善辉 教授(华南理工大学 发光材料国家重点实验室)
时间:2017年4月5日 下午4:20
地点:光电所二层报告厅
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报告题目:Quantum simulation based on trapped ions
报告人:申恒 博士(奥地利科学院量子光学与量子信息研究所)
时间:2017年3月31日 下午4:30
地点:光电所二层报告厅
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报告题目:亚散粒噪声极限偏振仪的研制
报告人:冯胜 教授(湖北工业大学)
时间:2017年1月3日 下午5:00
地点:光电所二层报告厅
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报告题目:半导体n-GaAs及碱金属铷原子中的自旋噪声谱研究———“倾听”自旋的噪音,探索材料的奥秘
报告人:马健 博士(中国科学院半导体研究所)
时间:2016年12月23日 下午5:00
地点:光电所二层报告厅
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报告题目:Coherent Interaction between Single-Photon and Cold
Atoms
报告人:张善超 博士(香港科技大学)
时间:2016年11月29日 上午10:30
地点:光电所二层报告厅
摘要:
Manipulate photon-atom interaction on quantum level lies at
the heart of modern quantum physics and quantum information
science. In this talk I may briefly introduce series of my
work related with single photons and mainly discussed the
work of single photon storage in cold atomic ensemble.
Firstly, a dark-line 2-dimensional magneto-optical trap and
long coherence time (~1us) heralded single photons source
will be presented. Followingly, improve optical quantum
memory in dense cold atomic ensemble will be discussed
mainly. In this work, benefit from the high optical depth of
the atomic ensemble and the high controllabity of single
photon waveform, we still kept the highest single-photon
storage efficiency around 50%. I also will briely present my
works including exploring the information speed limit of a
single photon utilizing optical precursor phenomena, direct
observation of photon absorption and reemission timing order
and improved DPS-QKD protocal. Finally,I will share very
shortly my current project in the ultracold degenerated Yb
atomic gases.
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报告题目:硅芯片上微光学腔系统中控制:理论与实验进展
报告人:张靖 副教授(清华大学)
时间:2016.11.24 下午5:00-6:00
地点:光电所二层报告厅
摘要:
硅芯片上微光学腔系统是目前微纳光子学领域研究的热点,围绕这一系统发现了很多新奇的物理现象,如光机械运动,声子激光,混沌等。报告将主要针对这一系统,介绍我们近期在理论与实验上取得的进展。主要包括两方面工作:(1)结合我们之前的工作提出的反馈非线性化的方法,近期我们发现,采用这一思想,可以在光机械系统中,打破系统的时空反演对称性(PT对称性),从而产生超低阈值的声子激光,并可用于传感,声子调控等,相关成果发表于物理顶级期刊Physical
Review
Letters等期刊;(2)结合我们之前提出的混沌扩频通信的方案,我们在近期的实验中实现了一种新的微纳光子学领域的弱光扩频方案。实验研究表明,利用光机械效应,可以实现混沌这一典型的强非线性效应从强光向弱光的传输,并在实验上首次观测到了光机械系统中的随机共振现象,这部分工作长文(Article)发表于Nature子刊Nature
Photonics,并被Nature Photonics选为2016年6月刊的封面论文。
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报告题目:超导量子相干器件和量子计算
报告人:刘玉玺 教授(清华大学)
时间:2016.11.24 下午4:00-5:00
地点:光电所二层报告厅
摘要:
经过近20年的发展,超导量子相干电路和超导量子计算取得了令人瞩目的跨越式发展。新设计的原型器件和相关的新物理现象接连涌现。量子比特相干时间从最初的纳秒级提升到百微秒级,寿命达到毫秒级。超导量子电路已达到了量子计算纠错的阈值条件并具有了容错功能。这些成就吸引了国际商业和政府机构的极大关注,比如谷歌,IBM,Intel等国际著名的公司开始设计和制造基于超导材料的量子信息处理器。本报告将基于超导量子电路过去的发展,结合个人的某些理论研究,对未来大规模超导量子信息处理在器件原理,量子仿真与纠错,信息的存储与操控,拓扑计算,量子程序运行等方面可能面临的一些理论问题做一梳理和探讨,以期进一步推动有关方面的理论研究。
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报告题目:光学微腔在高灵敏磁场检测中的应用
报告人:李贝贝 博士(北京大学物理学院)
时间:2016.11.19(周六)上午10:00
地点:光电所二层报告厅
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报告题目:Gravitational-Wave Detection Beyond the Standard
Quantum Limit via EPR Entanglement
报告人:马怡秋博士 (美国加州理工学院)
时间:2016.11.3(周四)下午4:30
地点:光电所二层报告厅
Abstract:
The Standard Quantum
Limit in continuous monitoring of a system is given by the
trade-off of shot noise and back-action noise. In
gravitational-wave detectors, such as Advanced LIGO, both
contributions can simultaneously be squeezed in a broad
frequency band by injecting a spectrum of squeezed vacuum
states with a frequency-dependent squeeze angle. This
approach requires setting up an additional long base-line,
low-loss filter cavity in a vacuum system at the detector's
site. Here, we show that the need for such a filter cavity
can be eliminated, by exploiting EPR-entangled signal and
idler beams. By harnessing their mutual quantum correlations
and the difference in the way each beam propagates in the
interferometer, we can engineer the input signal beam to
have the appropriate frequency dependent conditional
squeezing once the out-going idler beam is detected. Our
proposal is appropriate for all future gravitational-wave
detectors for achieving sensitivities beyond the Standard
Quantum Limit.
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报告题目:Time and frequency standard: Atomic Clock
报告人:Prof. Manzoor Ikram (National Institute of Laser and
Optronics,Nilore, Islamabad,Pakistan)
时间:2016.10.19(周三)下午5:00
地点:光电所二层报告厅
Abstract:
Cesium atomic beam clocks
have been the workhorse for many demanding applications in
science and technology for the past five decades. Tests of
the fundamental laws of physics and the search for minute
changes in fundamental constants, the synchronization of
telecommunication networks, and realization of the
satellite-based global positioning system would not be
possible without atomic clocks. The adoption of optical
cooling and trapping techniques, has produced a major
advance in atomic clock precision. Cold-atom fountain and
compact cold-atom clocks have also been developed.
Measurement precision of a few parts in 1015 has been
demonstrated for a cold-atom fountain clock. We present here
an overview of the Pakistan's time and frequency metrology
program based on cesium atoms. This activity consists of
construction and characterization of atomic-beam, and
several variations of cold-atom clocks. We discuss the basic
working principles, construction, and evaluation. We also
present here the research work towards compact atomic clocks
based on atomic coherence effects.
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报告题目:窄带非简并纠缠光源的制备
报告人:王健 博士 (中国科学技术大学)
时间:2016.10.15(周六)上午11:00
地点:光电所二层报告厅
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报告题目:基于离子阱的量子模拟与量子计算
报告人:崔金明 博士 (中国科学技术大学)
时间:2016.10.15(周六)上午10:00
地点:光电所二层报告厅
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报告题目:固体量子存储
报告人:李传锋 教授 (中国科学技术大学)
时间:2016.10.15(周六)上午9:00
地点:光电所二层报告厅
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报告题目:Studying strongly correlated quantum physics based on
ultracold strontium atoms
报告人:张熙博 副教授(北京大学量子材料科学中心)
时间:2016.9.21(周三)下午5:00
地点:光电所二层报告厅
摘要:
Since the creation of Bose-Einstein condensates, ultracold
atoms have been driving the quantum simulation of manybody
physics. However, the power of cold-atom experiments will be
enhanced even further by precision measurements, allowing
interaction physics and manybody physics normally probed at
nK temperatures to be studied at μK temperatures. This is
precisely what was recently achieved using cold strontium
atoms. On the basis of ultrastable lasers with 1×10-16
instability, the JILA strontium (Sr) optical clock realized
a powerful laboratory to study a spin system with manybody
dynamics. Here, s- and p-wave inter-atomic interactions are
characterized to high precision, enabling a spectroscopic
observation of SU(N £ 10) symmetry in 87Sr and
beyond-mean-field correlations at μK temperatures. This
study reveals a new route for pushing the frontier of
emergent many-body physics.
Going beyond experimental limitations
requires combining extraordinary measurement precision with
state-of-the-art techniques to cool, probe, and engineer
quantum gases. High-spatial-resolution imaging is one such
technique. It reveals equations of state and dynamics of a
quantum gas, and allows engineering arbitrary trapping
potentials for studying transport phenomena. I will discuss
how degenerate Sr gases provide unique opportunities to
explore strongly correlated quantum physics such as the
fractional quantum Hall effect.
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报告题目:Unveiling Microscopic Structure at Interface With
Better Surface Resolution
报告人:田传山 教授(复旦大学)
时间:2016.9.20(周二)下午5:00
地点:光电所二层报告厅
摘要:
Surface and interface under non-vacuum environment are
extremely important in nature and modern technology, for
instance, friction, corrosion, surface catalysis and
electrochemistry. Among very few available techniques that
can probe such surface/interface, Sum frequency spectroscopy
(SFS) has the advantages of being highly surface-specific
with sub-monolayer sensitivity. Surface resolution of SFS is
dictated by symmetry under electric dipole approximation.
However, there still exist challenges for the current SF
spectroscopy, which hinders advances of the field. In this
talk, I will discuss on the following two problems: (1)
Beyond the electric dipole approximation, the higher-order
electric-quadrupole bulk contribution to surface SF
generation may not be negligible. The problem has been the
lingering doubt for decades, and is particularly important
in dealing with media that do not have a strongly
polar-oriented surface layer; (2) The second challenge is
how to probe molecular structure of the first few monolayers
at charged interface, e.g. charged water interface. Such
atomically-thin layer governs the properties and
functionality of the interface, including electron and
energy transfer through interface in solar cell.
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报告题目:dark soliton in polariton BEC
报告人:薛艳 博士(吉林大学)
时间:2016年7月14日(周四)下午5:30
地点:光电所二层报告厅
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报告题目:Cross-Phase Modulation Based on Polarization-Sensitive
Rydberg Blockade
报告人:吴金辉 教授(东北师范大学量子科学中心)
时间:2016年7月14日(周四)下午4:30
地点:光电所二层报告厅
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报告题目:Cold atoms and hot quark-gluon plasma
报告人:王福强 教授(湖州师范学院理学院)
时间:2016年7月13日(周三)下午5:00
地点:光电所二层报告厅
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报告题目:Hybrid reduced-noise amplification and its applications
报告人:赵洁 博士(澳大利亚国立大学)
时间:2016年7月13日(周三)上午11:00
地点:光电所二层报告厅
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报告题目:Quantum computing and precision measurement in cold
atom traps
报告人:夏添 博士(中国科学技术大学)
时间:2016.7.7(周四)下午5:00
地点:光电所二层报告厅
摘要:
Part I: In University of Wisconsin-Madison, we have
developed a 2D array of optically trapped single atom qubits
for quantum computation experiments. We characterize single
qubit Clifford gate operations with randomized benchmarking
achieving global and site selected gates with fidelities
close to fault tolerance thresholds for quantum computation.
A two-qubit Rydberg blockade interaction provides a CNOT
gate which is used to create entangled Bell pairs. The
fidelity is characterized with parity oscillation
measurements.
Part II: A permanent electric dipole moment (EDM) of an atom
signifies the violation of both parity (P) and time-reversal
(T) symmetries. Measurements of atomic EDM open a promising
avenue towards new physics beyond the Standard Model. 225Ra
is an ideal case due to a strong nuclear octupole
deformation, making its atomic EDM more sensitive to
T-violating effects. 225Ra is radioactive with a half-life
of 15 days. 171Yb is a stable isotope with atomic properties
and transitions similar to those of 225Ra. It is
particularly useful as a proxy for testing various
measurement schemes and investigating systematic errors. We
propose to construct a cold Yb trap system for EDM
measurement.
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报告题目:Optomechanical devices for improving the sensitivity of
gravitational wave detectors
报告人:赵春农 教授(University of Western Australia)
时间:2016年6月28日(周二)下午5:00
地点:光电所二层报告厅
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报告题目:The role of Discord in Quantum Illumination
报告人:Jayne Elizabeth Donovan Thompson(National University of
Singapore)
时间:2016年5月31日(周二)下午5:30
地点:光电所二层报告厅
摘要:Abstract:Quantum
illumination, is a protocol which uses an entangled probe to
detect the presence (x= 0) or absence (x=1), of a faint
reflecting object which is bathed in intense noise.
Remarkably while the noise injected into this system
effectively kills all entanglement before the probe even
interacts with the reflecting object, this precursory
entanglement still helps us determine the value of x. This
is considered highly paradoxical. How can the benefits of
entanglement out-survive entanglement breaking noise?
In this talk I will show
that this paradox is resolved by a highly noise resilient
type of quantum correlations known as quantum discord --
i.e. quantum illumination works, precisely because even
after all entanglement in the initial probe state is
destroyed, discorded correlations survive. Indeed I will
show that there is a quantitative relation between the
amount of discorded correlations, used to store the value of
x, and the performance gap between quantum illumination and
the best classical illumination protocols. In doing so we
effectively kill two 'proverbial' birds with one stone. On
the one hand we demonstrate the role of discord as a
resource, in a prominent quantum protocol. On the other we
demystify quantum illumination, providing a new way to
understand and interpret this protocol.
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报告题目:Replicating the benefits of closed time-like curves
without Breaking Causality
报告人:Mile Gu(新加坡南洋理工大学)
时间:2016年5月31日(周二)下午4:30
地点:光电所二层报告厅
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报告题目:Photonic Maxwell's Demon
报告人:Prof. Vlatko Vedral(英国牛津大学)
时间:2016年5月31日(周二)下午3:30
地点:光电所二层报告厅
摘要:Abstract:In
my lecture I will explain the basis behind the relationship
between thermodynamics and (quantum) information theory. I
will show how our information about the system we are
manipulating allows us to extract work from it. I will then
discuss some basic results relating information to
thermodynamical work and illustrate this using the concept
of Maxwell's demon. Finally, I will present a quantum
optical experiment where a simple photon subtraction process
is used to gain information about the state of light which
is then fed forward to extract electrostatic work from a
capacitor. Understanding whether quantum physics offers any
thermodynamical advantages presents one of the main open
questions in this exciting field.
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报告题目:About states and modes in quantum optics
报告人:Prof. Claude Fabre(法国巴黎第六大学特级教授)
时间:2016年5月30日(周 一)下午4:00
地点:光电所二层报告厅
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报告题目:Spin-orbit coupling for ultracold atomic gases
报告人:Prof. Gediminas Juzeliūnas (Institute of Theoretical
Physics and Astronomy, Vilnius University, Lithuania)
时间:2016年5月10日(周二)下午5:00
地点:光电所二层报告厅
摘要:In
the initial part of the talk a background material will be
presented on the spin-orbit coupling (SOC) for electrons and
ultracold atoms. At present there is a great deal of
interest in the SOC affecting the centre of mass motion of
ultracold atoms. Subsequently we shall discuss some recent
developments in the area. One of current challenges is to
experimentally produce a two-dimensional (2D) SOC of the
Rashba type. We shall discuss a novel way of creating the 2D
SOC using a bilayer atomic Bose-Einstein condensate (BEC).
It is shown that an interplay between the inter-layer
tunneling, intra-layer Raman coupling, and intra-layer
atom-atom interaction gives rise to diverse ground-state
configurations for such a bilayer BEC. We shall also discuss
some other recent work in the area, including the
magnetically generated spin-orbit coupling.
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报告题目:The
utility of quantum technologies
报告人:张利剑 教授(南京大学现代工程与应用科学学院)
时间:2016年4月22日(周五)下午5:00-6:00
地点:光电所二层报告厅
摘要:
量子技术,如量子通信、量子计算和量子传感,具有突破经典技术局限并将其性能推进到最终极限的潜力,因而受到广泛关注。然而要在实际应用中实现这种潜力,我们仍然面临很多挑战,其中包括如何克服实验噪声对于量子技术的影响,以及拓展量子技术的应用范围从而将其应用于经典技术无法解决的问题。在该报告中,我将汇报我们在这两个方面取得的一些初步进展,包括对噪声环境下量子精密测量方案的研究,以及对于光场与表面等离激元耦合过程的量子描述。
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报告题目:迈向芯片化集成化量子信息技术
报告人:金贤敏 教授(上海交通大学物理与天文系)
时间:2016年4月22日(周五)下午4:00-5:00
地点:光电所二层报告厅
摘要:
量子信息技术有望实现无条件安全的保密通信,随计算位呈指数增加的超高速计算,超越标准量子极限的精密测量和传感等革命性的技术飞跃。然而,宏观光学器件的尺寸、稳定性和集成度等看似技术上的限制,其实根本性地使得量子信息技术仍然只是停留在小尺度的原理性演示阶段。在科学上,通过芯片化构建大规模的量子系统将使得人类能够探索全新的量子世界和领域;在技术上,芯片化的量子器件和系统是推动量子信息技术实用化的必然,进而依托量子信息技术推动信息技术变革。报告将介绍我们针对宏观量子光学系统走向集成芯片面临的新问题开展的研究,包括在上海交大搭建的飞秒激光直写光量子集成芯片2.0平台、全光纤低损耗光耦合网络和量子光源上取得的研究进展。
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报告题目:悬浮纳米球光力学系统检验CSL塌缩模型
报告人:李杰
(School of Science and Technology, Physics Division,
University of Camerino, Camerino (MC), Italy)
时间:2016年3月17日(周 四)下午4:00
地点:光电所二层报告厅
摘要:(波函数)塌缩模型[1]是一类理论假说,通过在薛定谔方程中引入一个非线性随机项(未知的塌缩噪声所致),用以解释宏观物体量子现象的缺失,是对经典量子力学的修正。当物体的尺寸(大小,内部粒子数等)大于一个值时(CSL模型设为100nm),塌缩噪声开始发挥显著作用,从而破坏量子叠加态,使得宏观量子现象难以观测。一些工作试图证明未知塌缩噪声来自引力(引力所致塌缩模型,Gravity
kills Schrodinger's
cat),但目前仍存在较大的争议,实验检验各种塌缩模型是判断其准确或真伪的唯一途径。
我们提供了一个理论方案[2],基于囚禁悬浮纳米球光力学系统,来检验目前最为流行的CSL塌缩模型。悬浮纳米球系统的优势是其Q因子极高,可达10^10,热噪声极小,从而(极小的)塌缩噪声与经典噪声可比拟,使得实验检验塌缩模型成为可能。
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报告题目:量子信息技术
报告人:郭弘
教授(北京大学)
时间:2016年3月16日(周
三)下午4:30
地点:光电所二层报告厅
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报告题目:Spin-Orbit
Coupling and Topological Phases for Cold Atoms: Theory and
Experiments
报告人:刘雄军
教授(北京大学)
时间:2016年1月18日(周一)下午4:30
地点:光电所二层报告厅
摘要:Cold
atoms with laser-induced spin-orbit (SO) interactions
provide intriguing new platforms to explore novel quantum
physics beyond natural conditions of solids. Recent years
have witnessed remarkable theoretical and experimental
progresses in the study of synthetic spin-orbit coupling and
exotic phases for cold atoms. In this talk, I will focus on
the realization of two-dimensional (2D) SO coupling and
topological phases, and introduce the recent experimental
progresses. This talk is organized in three parts. The first
part will briefly introduce the background of SO coupling
and topological phases in both condensed matter physics and
cold atoms. Then, I will focus on our recent scheme for
realizing SO interactions and exotic topological phases for
cold atoms. Finally, I will introduce the experimental
progress in observing 2D SO coupling and topological band
with 87Rb Bose-Einstein condensates in an optical lattice. |