诺奖得主Kip S. Thorne—LIGO探测器和引力波观测 |本周物理学术本周四在中国科学院大学中关村校区教学

1LIGO探测器和引力波观测

报告人：基普.索恩，加州理工学院

时间：12月20日（周三）15:00

单位：中国科学院大学中关村校区

地点：中关村教学楼s101

Kip.S. Thorne(基普.索恩)，美国理论物理学家，2017年诺贝尔物理奖得主。担任加州理工学院费曼理论物理学教授。美国文理科学院院士，美国国家科学院院士，俄罗斯科学院院士，美国哲学会会员。曾获邵逸夫天文学奖，基础物理突破特别奖，2017年度获得“复旦—中植科学奖”。2017年10月3日，因在LIGO探测器和引力波观测方面的决定性贡献，与Rainer Weiss, Barry Barish一起荣获诺贝尔物理学奖。

2Characterisation of the Surface Skyrmions in Chiral Magnets by Resonant Elastic Soft X-Ray Scattering

报告人：张石磊，University of Oxford

时间：12月19日（周二）14:00

单位：中科院物理所

地点：物理所M楼253

First, I will show that the surface skyrmions behaveunexpectedly different from that is found in the bulk. It presents multidomain state, and strong surface-pinning effect.Both effects are favoured by device applications. Second, I will demonstrate that REXS is able to reconstruct the very fine internal structure of an individual skyrmion, inaccessible to other magnetic characterisation techniques. This allows us to accurately measure the microscopic interactions of the material system. Lastly, I will show an in-situ REXS measurement by applying a magnetic field gradient, under which the skyrmions undergo concentric rotation with well-defined slow dynamics.This provides an effective way of controlling the skyrmions towards the racetrack memory embodiment.

3热力学过程以及生物震荡体系中的瞬态动力学

报告人：卢至悦，芝加哥大学

时间：12月19日（周二）14:30

单位：北京师范大学物理系

地点：物理楼106

近年来，非平衡稳态的体系被非平衡统计力学广泛描述。然而，实际生活中以及生命中的动力学过程往往是远离稳态的瞬态(transient)。我将详细讲述简单冷却过程以及复杂生物体系中两个有趣的瞬态现象。首先，我将利用随机热力学理论定义并且解释在同样条件下热物体比冷物体更先冷却的反常现象(generalized Mpemba effect) 。其次，我将从随机动力系统的角度探讨生物震荡体系(biological oscillator)处理外界信息的能力。并且探讨我们近期发现的广泛存在于生物信息处理过程中，生物体系抵抗内部热噪音与环境噪音之能力的不可兼得特性。

4Dissipation Dose Matter — A study on non-equilibrium phenomena in open cold atom systems

报告人：郑炜，University of Cambridge

时间：12月19日（周三），15:00

单位：中科院理论物理所

地点：新楼6420

I will first talk about the dynamics of fermions in an optical lattice with cavity induced hopping. For an infinite lattice, we find a superradiant phase with an infinitesimal pumping threshold which induces a directed particle flow. We explore the fate of this flow in a finite lattice with boundaries, studying the nonequilibrium dynamics including fluctuation effects. The short-time dynamics is dominated by superradiance, while the long-time behavior is governed by cavity fluctuations. We show that the steady state in the finite lattice is not unique and can be understood in terms of coherent Bosonic excitations above a Fermi surface in real space. Second I will discuss a cavity-induced dynamical optical lattice, in which the dynamical lattice is chosen to have a period that is incommensurate with that of an underlying static lattice. This dynamical lattice can be regarded as a dynamical version of the Aubry-Andr°‰e model, which can cause localization of single-particle wave functions. We show that atomic wave packets in this dynamical lattice generically spread via anomalous diffusion, which can be tuned between super-diffusive and sub-diffusive regimes. To understand this anomalous diffusion, we use the quantum trajectory picture to map the dynamics into a Le"vy walk with rests.

5Probing Cell Viscoelasticity

报告人：关东石，香港科技大学

时间：12月19日（周二），16:00

单位：北京师范大学物理系

地点：物理楼106

In this talk, the speaker will first review the contact mechanical measurement on living cells and tissues, and then introduce a unique technique of noncontact viscoelastic imaging of live cells using AFM with a long-needle glass probe. The probe tip interacts with the cell surface through a minute hydrodynamic flow in the nanometer-thin gap region between them without physical contact. This noninvasive and ultrasensitive method is capable of measuring cell height, volume, and Young’s modulus simultaneously. The experiment demonstrates that the long-needle AFM opens up a whole new realm of investigation at nanoscale for a range of interesting problems associated with the viscoelastic property of soft surfaces, such as those made of polymers, nano-bubbles, and living cells and tissues.

6加速器驱动先进核能系统及其关键材料研究

报告人：王志光，中科院近代物理研究所

时间：12月20日（周三）10:10

单位：中国科学院大学物理科学学院

地点：雁栖湖校区教1-114

7全球因特网的现状及未来展望

报告人：张立言，美国科珍通讯公司

时间：12月20日（周三）14:00

单位：中科院高能物理研究所

地点：化学楼C305会议室

当代因特网已经根本性地改变了全球国际社会，国际商务和人民生活，并将永存并成为我们生活不可或缺的一部分。因为因特网世界正在变为地球村。你是否想过每天你用智能手机送出的各种信息都是如何到达你朋友那边的？全球因特网的现状如何，及未来如何发展？那就敬请来听一个和曾经和你一样的理工男女，而不是专业计算机科学家的第一线故事。讲坐内容全面翔实，观点独特新颖。另外主讲人也会简单地讨论量子通迅，地面量子广域网和星地广域网。

8Entanglement, causality and energy conditions in QFTs

报告人：Huajia Wang，University of Illinois

时间：12月20日（周三）15:30

单位：中科院理论物理所

地点：新楼6420

It has become increasingly clear that the key to understanding many fundamental questions in quantum field theories (QFTs) is encoded in the underlying structure of entanglement and causality. In this talk, I will discuss a particular direction along such a line: tracing the quantum information and causality origins of energy conditions in QFTs. In particular, I will discuss two approaches to prove the averaged null energy condition (ANEC), one from entanglement constraint and the other from causality constraint. Furthermore, I will discuss how, by combining both elements and consider causality probed by the entanglement data, one can prove the stronger quantum null energy condition (QNEC).

9The Hall Effects Edwin Hall Never Imagined

报告人：金晓峰，复旦大学

时间：12月21日（周四）14:00

单位：清华大学物理系

地点：理科楼郑裕彤讲堂

The anomalous Hall effect (AHE) is one of the oldest and most prominent transport phenomena in magnetic materials. However, the microscopic mechanism of the AHE has remained unresolved for more than a century because its rich phenomenology defies standard classification, prompting conflicting claims of the dominant processes. We differentiate these processes through temperature-dependent measurements on epitaxial Fe, Ni, Co, and NixCu1-x films of varying thickness [1, 2]. The results allow an unambiguous identification of both intrinsic and extrinsic mechanisms of the anomalous Hall effect. The more recently discovered spin Hall effect (SHE) has attracted a great deal of attention because of its potential applications in spin current devices. Various methods have been developed to generate and detect the SHE and search for materials with large spin Hall angles. These efforts notwithstanding, reliable and accurate determination of spin Hall angle remains a challenge. In this lecture, I will first give a comprehensive discussion on the basic concepts of AHE and SHE. Exploiting the attributes of epitaxial magnetic thin films, I will then explain how to control independently the different scattering processes through temperature and layer thickness and to identify unambiguously the intrinsic and extrinsic mechanisms of the AHE. Finally, based on the understanding of the microscopic mechanisms of the AHE, I will describe how we developed a new method using H-patterned films to measure quantities inherent in the SHE.

10真空紫外电离质谱技术的基础和应用研究

报告人：胡勇军，华南师范大学

时间：12月21日（周四）15:00

单位：清华大学物理系

地点：理科楼三楼报告厅C302

真空紫外单光子电离是一种“软电离”技术。近年来，胡勇军教授领导的课题组应用该电离技术系统开展了激光解析-激光后电离质谱分子成像方法的研究。该方法中，应用一束红外激光（1064 nm）来解析气化生物样品，另一束真空紫外光（118 nm）对解析出的中性气体进行单光子电离。通过与飞行时间质谱仪和电控三维进样平台联用，实现了对小分子物质在生物组织中的质谱分子成像。此外，应用真空紫外光单光子电离和飞行时间质谱技术,以可调谐的红外激光作为激发光源，探测研究了气相中分子及其团簇的红外光谱和结构，结合理论计算，进一步探讨了氢键团簇内分子间相互作用力。

11Inflation Dynamics of quantum phase transition in a driven Bose-Einstein condensate

报告人：Cheng Chin，University of Chicago

时间：12月21日（周四）15:00

单位：中科院物理研究所

地点：M楼236报告厅

Quantum phase transitions are transitions between distinct many-body ground states, and are of extensive interest in research ranging from condensed matter physics to cosmology. Key features of the phase transitions include a stage with rapid growth of new order parameter, called inflation in cosmology, followed by the formation of topological defects.Based on Bose-Einstein condensates of cesium atoms in a shaken lattice, we report the observation of Kibble-Zurek scaling of quantum critical dynamics, and inflationary dynamics across the quantum critical point. In particular, the inflation manifests in the exponential growth and high harmonic generations of populations in well-resolved momentum states.

12Origin of broad-line regions: from torus to accretion disks

报告人：Jian-Min Wang

时间：12月21日（周四）16:00

单位：北京大学科维理天文与天体物理研究中心

地点：KIAA-PKU Auditorium

Active galactic nuclei are characterized by the prominent broad-line features from optical to ultraviolet bands. The broad emission lines are presumed to be from broad-line regions, but its origin has been one of well-known problem. I will extensively review this long-term problem and suggest a new scheme to tackle it.

13Precision measurement and quantum optics with long-lived atomic coherence

报告人：肖艳红，复旦大学

时间：12月21日（周四）16:00

单位：清华大学物理系

地点：理科楼郑裕彤讲堂

Atomic coherence originates from the superposition of quantum states of the atom and can enhance measurement sensitivity and enable low-light level quantum and nonlinear optics, thus has become a key resource in fields of precision measurements and quantum information science. In this talk, I will give several examples from our experiments using anti-relaxation coated atomic vapor cells with long coherence lifetime. For the precision measurement part, I will describe a sub-coherence-lifetime spectroscopy technique giving resonance linewidth of 0.1 Hz, and how we use it to achieve photon-shot-noise limited magnetometry. Ongoing experiments of breaking this limit using squeezed-light will be presented, as well as progress in preparing a large spin squeezed state. For the quantum optics part, I will show how atomic coherence transport can be employed to make a beam splitter for squeezed light, and how it mediates linear or nonlinear coupling of spatially separated light modes, giving rise to an anti-parity-symmetric optical Hamiltonian. In the end, I discuss future prospects in this unique system.

14味物理实验：新物理寻找

报告人：李海波，中科院高能所

时间：12月22日（周五）13:30

单位：中国科学院大学物理科学学院

地点：雁栖湖校区教1-304

15Combinatorial Strategies to Develop and Understand Metallic Glasses

报告人：Jan Schroers，Yale University

时间：12月22日（周五）14:30

单位：中科院物理研究所

地点：M楼236报告厅

In this talk, I want to focus on materials’ chemistry. For this, we will use combinatorial sputtering to fabricate large numbers of alloys simultaneously and subsequently use high-throughput methods to characterize the various alloys effectively. For most material classes, thin film effects and, more generally, fabrication specific effects, can dramatically affect structure and characteristic of the material. For metallic glasses, and that is one reason we focus on them here in this talk, this effect is much less pronounced and for some characteristics absent.

国内各大高校、科研机构物理学术讲座列表

2018年《物理》杂志开始征订啦！

轻松阅读享受《物理》

即日起订阅：《物理》原价240元/年

优惠价：180元/年

扫码订阅

十大热门文章

1.超强场下的正负电子对产生

2. 声学超构表面

3. 声学Mie共振及其应用

4. 宇称时间对称性声学

5. 超宽带声螺旋结构

6. 为什么浙江省高考学生选考物理人数大幅下降值得担忧 || 朱邦芬

7. 怀念卓益忠同志

8. 视界面望远镜：为黑洞拍下史上第一张“照片”

9. 超导“小时代”之二十五：印象大师的杰作

10. 物理学咬文嚼字之九十二：城邦与统计

END