1 在螺旋磁体中新颖拓扑磁结构观察及电流操控
报告人：田明亮，中国科学院合肥物质科学研究院
时间：11月15日（周二）15:00
主办：中山大学物理学院中子科学与技术中心
会议链接：https://www.koushare.com/lives/room/550197
摘要：
与传统磁畴相比，拓扑磁斯格明子（skyrmion）的磁矩呈涡旋状排列，可以产生单位磁性拓扑荷及演生电磁场，从而电子和磁斯格明子具有强相互作用，可以有效推动斯格明子运动，有望作为新型信息载体构筑高速度、高密度、低功耗磁存储器件。本报告将系统介绍磁斯格明子在受限体系中的产生机制和实空间结构表征以及电流对单个斯格明子的产生、驱动运动和擦除等精准操控等。本团队利用聚焦离子束微纳加工技术制备纳米条带器件，通过零磁场对斯格明子和螺旋磁畴混合态反转磁场的方法，成功在实验上实现了新型“磁束子”拓扑磁结构，利用洛伦兹透射电子显微镜原位磁结构观测及脉冲电流调控技术，首次实验获得并观察到具有不同拓扑荷的“磁束子”，在此基础上研究了纳秒脉冲电流驱动下“磁束子”的运动动力学行为等，为潜在的磁存储器件应用提供支撑。
报告人简介：
田明亮，中国科学院合肥物质科学研究院强磁场中心研究员/博士生导师。安徽大学物理与光电工程学院/院长。1986年武汉大学物理学专业本科毕业，1992年获武汉大学理学博士学位。1992-2000年在中国科学技术大学结构中心做博士后/副教授/教授。2000-2010年到美国宾夕法尼亚州立大学物理系及纳米尺度科学中心工作，先后任职纳米中心访问学者、助理研究员和物理系助理教授。2011年回国工作并受聘中科院强磁场科学中心。长期从事小量子体系在极低温和强磁场条件下的电荷和自旋输运研究，发表论文240余篇，其中在国际重要影响力NatureIndex期刊发表论文百余篇，总引用5000余次，H-因子40。曾受邀担任《JMMM》、《FrontiersinMaterials》、《Materials》等杂志编辑顾委委员、副主编及编委，中国物理学会低温物理专业委员会、磁学专业委员会以及科普委员会理事以及安徽省物理学会副理事长等。
2 探寻极端光
报告人：Gérard Mourou，École polytechnique Palaiseau France
时间：11月15日（周二）21:00
主办：Matter and Radiation at Extreme (MRE)
会议链接：https://www.koushare.com/lives/room/649759
摘要：
2018年诺贝尔物理学奖获得者巴黎综合理工大学Gérard Mourou教授介绍探寻极端光的工作。
3 拍摄超快分子电影
报告人：杨杰，清华大学化学系
时间：11月16日（周三）15:10
主办：北京大学物理学院
地点：物理楼中212教室
腾讯会议：445-443-5961
摘要：
“分子电影”指在原子级时空尺度上对分子结构演化的观测，是观测非平衡态光化学、光物理过程的一种新兴实验手段。为实现这一目标，需要同时达到飞秒时间分辨率与原子级空间分辨率。兆电子伏超快电子衍射（MeV-UED）是实现分子电影的一种前沿科学仪器。
在本报告中，我将介绍利用MeV-UED实现气相、液相分子电影方向的发展历程与最新突破。包括一系列气相小分子原子核波包的量子演化与液态水中的氢键运动。
报告人简介：
杨杰，清华大学化学系长聘副教授。2010年本科毕业于南京大学物理系，2016年博士毕业于内布拉斯加大学物理系。2016.6—2021.1在美国SLAC国家实验室工作，先后任助理研究员、副研究员、研究员。2021年 3月加入清华大学化学系。2021年10月获中国化学会物理有机化学新人奖。
4 Super-semiconductor: An Intriguing Conducting Material with Energy-saving Potential
报告人：Bingqing Wei，Department of Mechanical Engineering, University of Delaware, USA
时间：11月16日（周三）10:00
主办：Energy Materials期刊
会议链接：https://www.koushare.com/lives/room/503188
摘要：
Solid state materials can be categorized as conductors, semiconductors, and insulators based on their electrical conductivity. Breakthrough discoveries, such as superconductors (FeSe, YBCO, etc.) and topological insulators (HgTe, Bi2Te3, etc.), have led to the limit of conductivity falling by orders of magnitude or even to zero when certain extreme conditions are met. In this presentation, I will discuss a new set of semiconductors, i.e., super-semiconductors, which resistivity of ~10-8 W*m at room temperature is low enough to provide a basis for ultra-low-power electronic devices. PN junction diodes based on the super-semiconductors show unique properties compared to the pn junction diodes built upon traditional semiconductors, such as a near zero-threshold voltage of the pn junction diodes and a high breakdown field of ~ 1.1×106 V/cm. The super-semiconductor pn junction diodes are anticipated to apply to ultra-low-power electronic devices.
报告人简介：
Professor Bingqing Wei received his Bachelor’s degree (1987), M.S. (1989), and Ph.D. (1992) in Mechanical Engineering from Tsinghua University, Beijing, China. He is a Professor in the Department of Mechanical Engineering and serves as Director of the Center for Fuel Cells and Batteries at the University of Delaware, USA. He is the inaugural Field-Chief-Editor of Frontiers in Nanotechnology. Dr. Wei was an Assistant Professor in the Department of Electrical & Computer Engineering and Center for Computation & Technology at Louisiana State University from 2003 to 2007. He was a Research Scientist at Rensselaer Polytechnic Institute, Department of Materials Science and Engineering, and Rensselaer Nanotechnology Center from 2000 to 2003. Dr. Wei was a visiting scientist at Max-Planck-Institut für Metallforschung, Stuttgart, Germany, in 1998 and 1999. From 1993 to 2001, he was a faculty member at Tsinghua University in Beijing. Dr. Wei’s research interest and expertise lie in nanomaterials and nanotechnology. His research interests have focused on carbon nanostructure synthesis, processing, characterization, physical properties, and their applications in energy conversion and storage devices.
5 Radiation hydrodynamics and its prospects in planet formation and stellar evolution
报告人：Zhuo Chen，清华大学
时间：11月17日（周四）15:30
主办：北京大学物理学院
Zoom link: https://zoom.us/j/83104709301?pwd=NW1QTlhCZmJJbXBXaXVWdE9pUkgzQT09
Meeting ID: 831 0470 9301
Passcode: 652434
摘要：
Self-consistent radiation transfer and hydrodynamics is a very important but still under-explored field in computational astrophysics. In this talk, I will discuss some of the basic concepts of radiation hydrodynamics and equation of state (EoS). I will also present a novel 2D code, Guangqi, that can solve radiation hydrodynamics with a realistic EoS self-consistently. The code is thoroughly tested and applied to planet formation and stellar evolution. Accretion shocks and circumplanetary disks may exist in forming gas giants. By self-consistently modelling the radiation transfer and gas thermodynamics, we find that the molecular hydrogen may dissociate before being accreted, thus increase the initial entropy of the gas giants. In the meantime, a low temperature, low accretion rate, circumplanetary accretion disk may exist. For stellar evolution, people have detected a dozen of light-curves of luminous red novae (LRNe) as time-domain astronomy prospers. The progenitors of these LRNe could be close massive binary stars and the LRNe events are the manifestation of their merging processes. To better understand their radiation hydrodynamic process, we solve the radiation hydrodynamics and EoS self-consistently, and find that hydrogen recombination energy plays an important role in the shape of the light-curves of some LRNe, as well as the geometry of the merger's outflow.
报告人简介：
Zhuo Chen finished his undergraduate study at Tongji University in engineering mechanics in 2012, after that he studied mechanical engineering at the University of Rochester. He got his Ph.D. in physics and astronomy from the University of Rochester in 2018. Then he moved to the University of Alberta as a CITA National fellow. In 2020, he became a Shuimu Fellow and TAO fellow at Tsinghua University. Zhuo Chen's main interest is in high performance computing and radiation hydrodynamics.
转自：“中国物理学会期刊网”微信公众号
如有侵权，请联系本站删除！
