涌现能量转换效应、纳米线半导体量子材料、有效场理论 | 本周直播物理讲座

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报告人：Dr. Mingmin Yang, Center for Emergent Matter Science, RIKEN

时间：9月29日（周二）10:00

单位：中科院物理所

参加方式：讲座以线上形式进行，采用“腾讯会议”软件

会议ID：731 179 683

会议密码：0929

直播链接：

摘要：

Energy transduction has been an intensively and extensively studied topic for decades, due to its fundamental interests and technological importance. Just like any other physical effects, symmetry plays an essential role in the energy transduction. For instance, only the materials without inversion symmetry possess the piezoelectric effect that converts mechanical energy to electricity and vice versa; materials with polar symmetry possess the pyroelectric effect that generates electricity once sensing a temperature variation. Here, we would like to introduce three emergent energy conversion effects induced by symmetry engineering, i.e., the interface piezoelectric effect, interface pyroelectric effect and flexo-photovoltaic effect. The interface piezo-/pyroelectric effects manifest at any heterostructure interfaces once there develops a built-in field in the interface region, even though the component materials are centrosymmetric. The flexo-photovoltaic effect is the strain gradient mediated photovoltaic effect wherein the strain gradient breaks the inversion symmetry, giving rise to asymmetric distribution of photo-carriers in the k-space and thus, spontaneous photocurrent. These effects function in materials of any symmetry ranging from oxides, silicon, two-dimensional layered materials and even amorphous semiconductors, etc. More importantly, they exhibit coefficients in comparable and even larger than conventional bulk materials, demonstrating their potentials in technological applications.

报告人简介：

Dr. Ming-Min Yang graduated from the Department of Physics, University of Warwick (UK) in 2018 and now works in the Center of Emergent Matter Science, RIKEN (Japan) as a postdoctoral researcher. Dr. Yang’s research interests focus on the novel physical phenomena and effects arising from symmetry breaking, including energy transduction and quantum transport, etc., as well as their coupling with material properties. Together with cooperators, Dr. Yang has developed three fundamentally new energy conversion effects, i.e. flexo-photovoltaic effect, interface piezoelectric effect and interface pyroelectric effects, and has published 10 papers as the first author or corresponding author including 2 papers in Nature and 1 paper in Science.

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报告人：刘罡，北京高压科学研究中心

时间：9月29日（周二）14:30

单位：山东大学物理学院

地点：知新楼C座 7楼量子报告厅

摘要：

自古至今，人类历史的发展阶段可以按照使用材料的特点来划分，材料科学的发展也不断推动着人类文明的进步。材料科学上可衔接物理学，化学，生物学等基础科学的最新成果并反哺其发展，下更是与工业技术、产业升级等需求牵引性领域紧密联系。对于材料科学而言，压力作为热力学基础维度之一，毫无疑问会影响材料的结构，从而进一步通过构性关系决定功能材料的性能。每个物质到了数百万巴的压力，会历经多种新结构与新相。这些高压相的性质和价值极端互异。犹如石墨之异于金刚石。如此每一个压力阶段，各有一套全新的物质世界。如我们深入探讨，人类所知的整个材料科学，在高压空间里，将扩大十倍有余。自有无穷的尖端材料可待发明。

报告人简介：

刘罡，北京高压科学研究中心研究员（Staff Scientist, Principle Investigator），于2013年获得哈尔滨工业大学航空宇航科学与技术博士学位，之后进入美国卡内基研究员、美国阿贡国家实验室工作、于2018年底进入北京高压科学研究中心工作至今，现为研究员、课题组长。

报告人致力于先进同步辐射表征技术和极端环境条件下的材料科学研究，并专注于材料性能背后的物理机制。在此基础上，发表论文40 余篇，其中通讯/第一作者论文20 余篇，论文包括3 篇PNAS、 Nature Communications、 Materials Today、Materials Science and Engineering R：Reports、Advanced Functional Materials、Applied Physics Reviews 、ACS Energy Letters 、Journal of Physical Chemistry Letters 等知名期刊。三篇论文被选为杂志封面论文。报告人的学术成果被包括Nature、Science 等期刊广泛引用，并被中国科学报、Advanced Science News 等多家学术媒体及我国工信部等政府媒体作为学术亮点进行报导。发表在Applied Physics Reviews 上研究论文被编辑部选为Featured paper。多项成果作为重要进展入选中国工程物理研究院学术年报和上海光源开放十周年纪念文集，并连续多年入选中科院大科学装置年报。报告人与合作者获中国工程物理研究院2019 年度科技创新奖Top10 和中国工程物理研究院2019 年度科技创新一等奖。

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报告人：庄乾东，Lancaster University

时间：9月29日（周二）19:30

单位：中国科学院半导体研究所

参会方式：蔻享直播

直播链接：

摘要：

Nanostructured semiconductor materials have attracted increasing attention in the last decade due to theirunique functionalities and the promising potential as new building blocks fornext generation devices. Of particular interest is the III-V compound semiconductor nanostructures such as quantum dots, nanowires and their integration with Si platform or newly emerged 2D materials. The combination has advantages to exploit the unique optical and electronic functionality of III–V technology with the advanced signal processing capabilities and low-cost volume production techniques associated with silicon. This talk will brief our recent research outcomes on several novel semiconductor quantum materials, ranging from quantum dots to nanowires and hybrid material systems with device applications in energy harvesting, lasers, photodetectors and quantumt echnology. Advanced monolithic hybrid structures of InAsSb nanowire-based quantum materials on silicon will be specifically discussed, followed by the demonstration of proof-of-concept devices in infrared photodetection. Thepotential further device applications will be also briefed.

报告人简介：

Dr Qian-Dong Zhuang is a Reader in the Physics Department at Lancaster University, UK, Head of Semiconductor Quantum Materialsand Device in Lancaster Quantum Technology Centre. He gained his PhD from the Institute of Semiconductors, CAS, China in 1999. Since then he worked at Nanyang Technological University (Singapore) and Glasgow University (UK) as a Research Scientist. In 2003, he joined Lancaster University as a Lecturer. He has subsequently established MBE Research Laboratory (molecular beam epitaxy) in the Physics Department where he has been leading the research in semiconductor quantum materials and devices. His current research is focused on III-V compound semiconductor quantum materials and device applications, with specific interest in quantum dots, quantum rings, nanowires and hybrid integration with silicon, for advanced optoelectronics. He has published 2 book chapters and more than 100 papers in peer-reviewed scientific journals including Nature Communication, Nano Letters, Advanced Functional Materials, Nano Research, Applied Physics Letters and Physical Review B. He is an Editorial Board Member of Nature Scientific Reports and IoP Journal of Semiconductors.

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报告人：史蒂芬·温伯格，德克萨斯学奥斯汀分校

时间：9月30日（周三）22:00

单位：中科院高能物理研究所、浙江大学

参会方式：蔻享直播

直播链接：

摘要：

史蒂芬·温伯格（Steven Weinberg）是德克萨斯大学奥斯汀分校的物理学和天文学教授。他在量子场论，粒子物理，引子理论，超对称，宇宙学等多个方向做出了奠基性的工作。他在1967年发表的文章《A Model of Lepton》标志了粒子物理标准模型的诞生，他本人因此荣获1979年诺贝尔物理学奖。除此之外他还是美国国家科学奖章，本杰明法兰克林奖章，丹尼尔海涅曼数学物理奖，基础物理特别突破奖等众多奖项的获得者。他著有《场的量子理论》、《引力论和宇宙学》、《量子力学讲义》、《宇宙学》等物理学教材的传世之作，同时他还是畅销科普书籍《最初三分钟》、《终极理论之梦》等的作者。他在科普人文方面的工作获得了路易斯·托马斯科学家诗人奖和其它奖项。本报告是温伯格教授应邀为“All things EFT…”系列线上研讨会做的开幕式报告，报告人将结合自身的工作回顾有效场论思想从诞生到成为量子场论核心概念和方法的历程。