报告人简介：秦华军博士于2005年在湖南师范大学物理系获本科学位。于2011年在中国科学院物理研究所获得博士学位，导师为吴克辉研究员。2011年5月-2015年4月在德国Max-Planck微结构物理研究所做博士后研究，导师为Kirschner教授。2015年5月在芬兰Aalto大学Sebastiaan教授研究组继续做博士后研究。在博士期间，主要应用高能量和高动量分辨率的角分辨电子能量损失谱对铜氧超导体中的电-声子耦合以及低维金属体系中的等离激元进行系统的研究。在博士后期间，主要应用自旋极化电子能量损失谱对铁磁金属薄膜中的表面磁激子（Magnons）进行系统的研究。

Abstract: Elementary magnetic excitations (magnons) are essential for understanding many fundamental magnetic properties and technological applications in magnon-based devices, ultrahigh-density magnetic recording, magnetic tunneling junctions, and so on. To probe high energy magnons, spin-polarized electron energy loss spectroscopy (SPEELS) is a powerful tool due to the capability of measuring magnons over the whole surface Brillouin zone and the capability of investigating spin-dependent scattering.

In this talk, the concept of magnons, SPEEL-spectrometer, and the mechanism of magnon excitations are introduced firstly. The magnon measurements in ultrathin FePd alloy films grown on Pd(001) are then presented. It is observed that the magnons’ energy can be largely tuned by varying Fe concentration. And the magnons’ lifetime in ultrathin FePd alloy films is rather long compared to the one in Fe films grown on other substrates. First-principles calculations revealed that the long magnons’ lifetime has its origin in the peculiar electronic hybridizations between Fe and Pd atoms. These electronic hybridizations lead to the suppression of the relaxation channels of high energy magnons and result in a long magnons’ lifetime. Finally, the temperature dependence of such long-lived magnons is also presented. Up to 400 K (1.2 Curie temperature), the magnons are still efficiently excited. The renormalization of magnons’ energy and lifetime as a function of temperature is observed, but weaker than that reported.

报告简介

过去十年，涌现了一系列新型量子材料，这些材料表现出和传统材料不同的新奇电子结构和显著的量子效应，成为凝聚态物理研究的热点，例如石墨烯、拓扑绝缘体、铁基超导体等。这些新型低维量子材料的发现，开辟了自旋、超导和拓扑相结合的多个激动人心的新领域。与传统材料的一个重要不同是，因为这些新体系的主要特征和量子效应都集中体现在其表面和界面上，因此只有获得原子级高质量的薄膜样品，才有可能开展后续的实验研究。本报告中，我将介绍我们依靠自主研发制造的高性能分子束外延（MBE）系统、扫描隧道显微镜/扫描隧道谱（STM/STS）系统，以及利用这些系统开展的新型层状材料生长、原子尺度的新奇物性的研究。并着重介绍近年来在硅烯领域的一些工作，包括在国际上最先制备出硅烯、并利用STM/STS揭示出硅烯的一系列特异性质，如线性色散、六角翘曲的Dirac锥、背散射抑制、低温相变等。

个人简介

吴克辉，男，1973年10月生，中科院物理所研究员、博士生导师、表面物理国家重点实验室课题组长。2004年10月受中科院“百人计划”支持，在中科院物理所表面物理国家重点实验室开展工作。研究方向为新型量子材料的分子束外延（MBE）生长及其原子尺度物性的扫描隧道显微学研究。发表SCI论文70多篇，总引用1600多次，有7篇论文入选ESI高引论文(Highly cited papers)。曾获中科院杰出科技成就奖（2011）。

课题组网页http://surface.iphy.ac.cn/sf09/index-cn.html

Abstract

An atomic-scale understanding of gas adsorption mechanisms on metal-porphyrins or metal-phthalocyanines is essential for their practical application in biological processes, gas sensing and catalysis. Intensive research efforts have been devoted to the study of coordinative bonding with relatively active small molecules, such as CO, NO, NH₃, O₂ and H₂. However, the binding of single nitrogen atoms has never been addressed, which is both of fundamental interest and indeed essential for revealing the elementary chemical binding mechanism in nitrogen reduction processes. Here, we present a simple model system to investigate, at the single-molecule level, the binding of activated nitrogen species on the single Mn atom contained within the manganese phthalocyanine (MnPc) molecule supported on an inert graphite surface. Through the combination of in situ low-temperature scanning tunneling microscopy, scanning tunneling spectroscopy, ultraviolet photoelectron spectroscopy, x-ray photoelectron spectroscopy investigations and density functional theory calculations, the active site and the binding configuration between the activated nitrogen species (neutral nitrogen atom) and the Mn center of MnPc is investigated at the atomic scale.

Dr. CHEN Wei is currently an Associate Professor (2013 - ) in both Chemistry Department and Physics Department at National University of Singapore (NUS). He received his Bachelor’s degree in Chemistry from Nanjing University (China) in 2001, Ph.D. degree from Chemistry Department at NUS in 2004. His current research interests include Molecular-scale Interface Engineering for Molecular, Organic and Graphene Electronics, and Interface-Controlled Nanocatalysis for Energy and Environmental Research. He has also published more than 160 papers on high-impact peer-reviewed journals in these topics, including 11 invited review articles, and receiving over 4000 citations with H-index of 35.

Email: phycw@nus.edu.sg

报告题目：英国南威尔士大学WORIC中心光电子研究进展

摘要：英国南威尔士大学是由格拉摩根大学和威尔士新港大学合并而成,其前身有100多年历史。其已成为英国威尔士最大的大学，也是英国本土最大的几所大学之一。其一流的教学和科研水平已得到了众多国际久负盛名的专业协会的认证。这些协会包括英国特许公认会计师公会、英国计算机协会、皇家采购与供应学会、英国工学技术学会、英国工程委员会、英国消防安全工程学会以及皇家特许测量师学会。本报告主要涉及近年来在英国南威尔士大学无线和光电子研究创新中心（WORIC）所从事的创新性研究。主要包含高功率蓝绿激光器、高效OLED器件、无跳模可调谐激光器、无人机光学数据传输、扫频干涉测量系统、新颖的全波长转换装置等。

报告人简介：Nigel Copner是南威尔士大学无线和光电子研究创新中心的首席教授,是Cymtec公司的创始人，同时也是Global Laser、Oclaro和 Optoplex等公司的技术顾问。他主要从事激光光电子学和微纳光子学在精密测量、通讯、光源、生命科学领域的应用研究。他曾经在DERA、RENISHAW、JDSU等公司工作，目前拥有40多项专利。他的许多专利已被成功商业化，每年创造经济价值高达1千万美元。他的全光转换技术 (US2001006568)是目前市场上最畅销的光-机转化产品的核心技术; 他的Dispersionless Interleave技术在市场上占很大份额，是众多DPSK/DQPSK生产线的基础(US2002154314、US2002171908); 他的倍频技术(US2004131093)是美国JDSU公司蓝绿激光的核心，蓝绿激光也是JDSU公司最销量的激光产品之一。同时，Copner教授热爱教育事业，他目前在南威尔士大学开展光电子学研究生和博士课程。该课程面向全球学生，并为毕业生提供在英国知名光电子公司实习半年的机会，旨在为培养下一代科学家和工程师做一份贡献。

报告人：Dr. David Huang(黄英强博士)

报告人简介：

Previous Director of Medical Physics and RSO at Memorial Sloan-Kettering Cancer Center and Visiting Professor at Various Universities in US, China and Taiwan; Current professor and director of Medical physics Graduate program at DKU.

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