超导量子干涉器件、阿尔法磁谱仪、对称性破缺、滑移/摩尔铁电 | 本周物理讲座

报告人：孔祥燕，宁波大学

时间：1月2日（周二）15:00

单位：中科院物理所

地点：M236会议室

摘要：

超导量子干涉器件（SQUID）是基于约瑟夫森效应和磁通量子化的高灵敏度磁传感器，由于其优越的性能，在量子信息、量子探测方面有广泛的应用。本报告将介绍SQUID基本原理、设计原则、制备工艺及难点，以及在弱磁探测如生物磁（心磁、脑磁、肌肉神经磁场）探测、工业无损检测、精细电流成像、地球物理探测等领域的国内外进展，并对目前在高端仪器装备研发方面的关键技术和瓶颈问题展开分析和讨论。

报告人简介：

2005 年 8 月在中国科学院物理研究所获得博士学位；2005 年 9 月至 2010 年 3 月在日本大阪大学从事博士后研究；2010年4月进入中国科学院上海微系统与信息技术研究所工作。2018年11月进入宁波大学信息科学与工程学院工作。从事弱磁传感器及其在生物磁探测、无损检测、地球物理等领域的应用研究。研制国内首套多通道心磁图仪并推进临床应用和产业化。国内外期刊发表学术论文70余篇。申请国内专利100余项，授权50余项。为IEC-TC90 WG14 委员、全国专业标准化技术委员会委员、中国电子学会超导电子学分会会员、IEEE CCCSC member。

报告 人：张波，南京大学

时间： 1月2日（周二）12:00

单位：江苏省物理学会

链接： https://www.k‍oushare.com/lives/room/061679

摘要：

Active matter is a new class of intrinsically non-equilibrium systems whose components transduce energy from the environment into mechanical motion at its single unit level. The remarkable feature of active matter systems is their natural ability to collectively change structures, self-heal and environmentally adapt in response to external stimuli on a much larger scale than their unit sizes. Self-assembled active soft materials provide a unique opportunity for materials science since it permits materials far more complex than traditional solid-state materials, with many levels of functionalities, hierarchical organizations and compartmentalization so far observed only in biological systems. In this talk, I am going to present our recent progress in reconfigurable collective behaviors in active soft matter, focusing on developing a set of principles that facilitate the control and manipulation of emergent active states via temporal modulation of activity and shape-anisotropy of particles. Our work provides new fundamental insights into mechanisms of spontaneous formation of collective states in active matter systems and offers new prospects for the design pathways of active synthetic materials and soft robotics relying on the use of dynamic self-assembly and re-configurability.

报告人简介：

张波，南京大学物理学院准聘副教授，博士生导师。2012年获南京大学材料物理学士学位，2018年获美国明尼苏达大学材料科学与工程博士学位，之后先后任美国Argonne国家实验室、美国西北大学博士后研究员。2022入选国家海外高层次青年人才项目，2023年入职南京大学物理学院。主要从事软物质方面的实验研究。目前已在Nature Physics, Physical Review Letters, Nature Communications等国际一流学术期刊上发表论文10余篇。

报告人： 马寅哲 ，Stellenbosch University 

时间：1月3日（周三）15:00

单位：中科院理论物理所

地点：南楼 6620

摘要：

Dark matter is the dominant matter in the Universe but its nature is still unknown. In recent years, indirect detection search, especially using radio telescopes becomes a main stream of searching for dark matter candidates. In this talk, I will introduce three major scenarios of dark matter widely considered as the dark matter candidates: Axion-Like-Particles (ALP), Axion dark matter and WIMP (Weakly Interactive Massive Particle) and show what mechanism they can manifest and radiate the radio waves that are possibly detectable with mid-frequency radio telescopes. I will then discuss how the current radio telescopes, such as FAST, MeerKAT and SKA can search the DM candidates and  put constraints on their physical parameters.

报告人简介：

Professor Yin-Zhe Ma research focuses on observational and theoretical cosmology aimed at understanding the fundamental laws of the Universe and uncovering the nature of dark energy and dark matter. He is currently a core member of the Square Kilometer Array (SKA) Science Working group, the Planck science team, Hydrogen Epoch Reionization Array (HERA), and the CMB Stage-4 experiment and LSST (Vera C. Rubin Observatory). With the Planck science team, he was awarded the 2018 “Gruber Cosmology Prize” by the IAU. He has published over 120 papers, with total citations exceeding 26000, h-index 45. He was awarded the NSFC Oversea Scholar grant and several South Africa National Research Foundation grants. He was elected to the Academy of Science of South Africa in 2022.

报告人：Ping Chen，魏茨曼科学研究所

时间：1月3日（周三）15:30

单位：北京大学物理学院

地点 ： KIAA-Auditorium

摘要：

Although looking serene to human eyes, the night sky appears as a spectacular cosmic firework display. These fleeting phenomena, known as astronomical transients, reveal them across the whole electromagnetic spectrum. A large fraction of these transients are canonical supernovae (SNe) or other exotic stellar explosions. Unraveling the intricacies of how these explosion phenomena emerge and identifying their celestial sources has become one of the focal points in modern time-domain astronomy, which can reveal a great deal about the universe, from how matter and force behave in the most extreme conditions to how the cosmos evolved.

In this talk, I will talk about recent observational progress in understanding the final explosion of stars, including thermonuclear explosion of white dwarfs, core-collapse of massive stars, and the new emerging population of fast-evolving transients with unknown origins. I will discuss observations spanning from the initial moments shortly after the explosion to very late times. I will show that observations in different phases of the transients allow us to probe different aspects of the explosion phenomena. For example, the infant phase probes the ambient environment and nebular phase penetrates the innermost ejecta of the explosion. In this talk, I will highlight two recent discoveries, I will highlight two recent discoveries, the periodicity in a stripped envelope SN 2022jli and the minute-duration optical flare in the late time of a luminous fast blue optical transient AT 2022tsd, which show the importance of the newly formed compact object (neutron star or black hole) in the aftermath of stellar explosion.

报告人简介：

Dr. Ping Chen is a Benoziyo fellow at the Weizmann Institute of Science. He graduated from the Department of Astronomy of Peking University in 2021. He has broad interest in observational studies on cosmic explosions especially supernovae.

报告 人：王健，北京大学

时间： 1月3日（周三）16:00

单位：清华大学高等研究院

链接： https://www.kous‍hare.com/lives/room/131662

摘要：

The pair density wave (PDW) is an extraordinary superconducting state where Cooper pairs carry nonzero momentum. Theoretically, the PDW order is hypothesized to play a fundamental role in high-temperature superconductors. Here, using scanning tunneling microscopy/spectroscopy, we report the discovery of the PDW state in monolayer iron-based high-Tc Fe(Te,Se) films grown on SrTiO3(001) substrates. The PDW state with a period of λ ~ 3.6aFe (aFe is the distance between neighboring Fe atoms) is observed at the domain walls by the spatial electronic modulations of the local density of states, superconducting coherence peak height and gap energy. Moreover, the π-phase shift boundaries of the PDW state are observed near the vortices of the induced secondary charge density wave state, further demonstrating that the PDW state at the domain wall is a primary state. The discovery of the primary PDW state in the monolayer Fe(Te,Se) film provides a low-dimensional platform to study the PDW state and its interplay with the topological electronic states and unconventional high-Tc superconductivity.

报告人简介：

Dr. Jian Wang is a Boya Distinguished Professor of Physics at Peking University. He developed two laboratories at Peking University to perform ultralow temperature-high magnetic field transport measurements and low temperature scanning tunneling microscopy/spectroscopy-molecular beam epitaxy investigations. Dr. Jian Wang’s current research interests are quantum transport properties of low dimensional superconductors and topological materials. He has discovered a series of emergent quantum phase transitions and quantum states in both low dimensional superconductors and topological materials, including quantum Griffiths singularity, bosonic anomalous (quantum) metal state, topological zero energy bound states and pair density wave states in two dimensional superconductors, as well as log-periodic quantum oscillations, high Chern number and high temperature Chern insulator states in topological materials. Dr. Jian Wang authored more than 130 papers in Science, Nature, Nature Physics, Nature Materials, Nature Nanotechnology, Science Advances, Nature Communications, PNAS, Physical Review X, Physical Review Letters, etc. He has given more than 100 invited talks and was awarded Sir Martin Wood China Prize in 2015, Changjiang Distinguished Professor of China’s Ministry of Education in 2016, Outstanding Achievement Award for Research in Institutes of Higher Education of China (Young Scientists) in 2019, and the Achievement in Asia Award (Robert T. Poe Prize) in 2022.

报告人： Prof. Jingsheng Chen ，  National University of Singapore 

时间：1月5日（周五）9:30

单位：中科院物理所

摘要：

Electric manipulation of magnetization is essential for the integration of magnetic functionalities in integrated circuits. Spin-orbit torque (SOT), originating from the coupling of electron spin and orbital motion through spin-orbital interaction, is able to effectively manipulate magnetization. Symmetry breaking plays an important role in spintronics based on SOT. SOT requires inversion asymmetry in order to have a net effect on magnetic materials, which is commonly realized by spatial asymmetry: a thin magnetic layer sandwiched between two dissimilar layers. This kind of structure restricts the SOT by mirror and rotational symmetries to have a particular form: an “antidamping-like” component oriented in the film plane even upon reversal of the magnetization direction. Consequently, magnetization perpendicular to the film plane cannot be deterministically switched with pure electric current. To achieve all-electric switching of perpendicular magnetization, it is necessary to break the mirror and rotational symmetries of the sandwiched structure.

报告人简介：

Jingsheng Chen is currently a professor with Department of Materials Science and Engineering, NUS. He obtained his Ph.D degree in 1999 in Lanzhou University, China and joined NUS in December 2007. During 2001-2007 he worked at the Data Storage Institute as a research scientist. He has authored/co-authored more than 300 refereed journal papers including Nature, Nature Nanotechnology, Nature Comm. Science Advance, Advanced Materials, Physical Review X, Physical Review Letter etc., 3 book chapters, holds over ten patents and has made more than 100 invited presentation in the international conferences. His research work has obtained more than 13000 citations with H index of 61. His research interest includes magnetic and oxide based non-volatile memories, spintronics, ferroelectric tunnel junction, strongly correlated oxide materials. He secured more than S$17 million research grants from government and around US$ 1 million from Seagate Technology and more than S$ 1 million from Globalfoundries. The magnetic recording media in the newest generation of HDD (HAMR) applied a few of his inventions. He is 2022 IEEE Magnetic Society Distinguished Lecturer.

报告 人：张华侨，中国科学院高能物理研究所

时间： 1月5日（周五）10:00

单位：上海交通大学物理与天文学院 李政道研究所 北京大学物理学院 高能物理研究中心

链接： https://www.koushare.com/‍lives/room/284118

摘要：

Under the local gravitational field, perturbations from high-frequency  gravitational waves can cause a vertical shift of the Mossbauer  resonance height. Considering a stationary scheme with the Ag-109  isotope, we demonstrate that the extremely high frequency precision  in Mossbauer resonance allows for competitive gravitational wave  sensitivity from KHz up to above MHz frequencies. Mossbauer  resonance can offer a novel and small-sized alternative in the quest of  multi-band gravitational wave searches.  

报告人简介：

张华桥，中国科学院高能物理研究所研究员，博士生导师，中国CMS 组副协调人。2003 年学 士 毕业于武汉大学，2008 年博 士 毕业于中科院 高 能物理研究所与法国艾克斯-马赛第二大学，2008-2010 年在法国马赛粒子物理中心做博 士 后，2010-2013年在美国密西根州立大学做博 士 后，2013 年至今在中科院高能物理研究所工作。主要研究方向为 LHC 实验上希格斯物理、顶夸克物理、 新物理寻找和先进量能器研制，主持 CMS 高粒度量能器北京硅模块中 心 工作。

报告 人：张宏浩，中山大学物理学院

时间： 1月5日（周五）17:00

单位：中国物理学会、北京师范大学科学教育研究院

链接： https://www.koushare.com/lives/room‍/375325

摘要：

暗物质在宇宙中的含量约是可见物质的五倍，但我们现在仍然对暗物质知之甚少，在粒子物理的标准模型中也找不到合适的暗物质候选粒子，暗物质之谜是当前科学研究前沿的一个热点课题。阿尔法磁谱仪是安装在太空中的一个先进的粒子物理探测器，它可以测量高能量的正电子、电子、反质子、质子、各种原子核等多种宇宙线粒子，这些粒子的其中一部分可能是暗物质湮灭或衰变的产物，从而可望在阿尔法磁谱仪上实现对暗物质的捕捉探测。本期报告将介绍暗物质的基础知识，阿尔法磁谱仪的科学装置、物理原理、科学目标、研究成果以及未来的研究展望。

报告人简介：

中山大学物理学院人才引进小组成员，中国物理学会高能物理分会委员， 《物理与工程》、《Symmetry》、《AAPPS Bulletin》等国内外期刊编委。

1998-2002年清华大学物理系本科,2002-2007年清华大学物理系博士。2007年至今在中山大学任教。 

主要研究方向是粒子物理与场论,特别是暗物质、有效场论、复合希格斯、额外维、超出标准模型的新物理等。课题组是国际上最早运用有效场论方法对暗物质开展唯象学计算分析的研究小组之一,其在这方面代表性研究论文获得了国际同行的大量引用。

报告人：吴梦昊，华中科技大学物理学院

时间： 1月8日（下周一）10:00

单位：中科院物理所

地点 ： M236

摘要：

二维铁电体有望解决现有铁电体和微电子电路结合的瓶颈问题，并给数据读写方式带来革命性变化。报告人将介绍几个典型的二维铁电理论设计，包括提出独特的滑移铁电机制，普适存于一系列范德华双层和多层中，使大多非铁电二维材料可以特定堆叠诱导层间不对等，产生一种在电场下以层间水平滑移翻转的垂直铁电，在层间扭角下还会产生一种铁电莫列超晶格，呈现周期性规整铁电畴，随后被一系列重要实验在多种二维多层体系证实(已有20篇实验文章发表于Nature、Science和子刊)；其铁电还可和层内磁性、激子、谷极化、拓扑性质等耦合并加以调控。近来还发现某些体系邻层堆叠构型是对称的，但隔层堆叠构型却能产生对称破缺和垂直极化，在电场下仍可驱动层间滑移使铁电翻转，有望解释一系列实验现象。

报告人简介：

吴梦昊于2007年毕业于南京大学获得学士学位，2011年毕业于内布拉斯加大学林肯分校获得博士学位，之后三年在弗吉尼亚联邦大学及麻省理工学院从事博士后研究工作，2014年加入华中科技大学物理学院任教授，博士生导师。主要从事二维铁电/多铁的理论研究，并有一系列相关预测随后得到实验证实。目前以通讯作者在Nat Rev Phys、Nat Commun、Sci Adv、PNAS、Natl Sci Rev、PRL、JACS等期刊发表文章60余篇，入选Elsevier中国高被引学者。