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【周惠久论坛】邀请讲座人: 吴军桥教授

2017-06-09 17:31:05

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邀请讲座人:吴军桥教授

简介: 吴军桥,教授,复旦大学物理学学士学位,北京大学物理学硕士学位,美国加州伯克利大学材料科学博士学位,美国哈佛大学物理化学专业博士后。2006年至今,在美国加州伯克利大学材料科学系担任教授,兼劳伦斯伯克利国家实验室研究员;2015年受聘为教育部第十四批长江学者讲座教授,同年受聘为清华-伯克利深圳学院纳米能源材料实验室Core PI,并担任环境科学与新能源技术中心副主任。主要奖项有:伯克利奖、Ross N. Tucker奖、美国国家基金会Career奖、美国能源部Early Career奖、2013年美国总统青年科学家奖(PECASE,美国政府授予青年科学家的最高奖项)、2015年北京大学优秀校友奖、 2017年 Bakar Faculty Fellows。 研究方向:半导体与纳米材料科学技术,强关联电子材料的低维效应、纳米尺度的相变,以及半导体复合材料的热电性能和光伏性能。迄今在国际一流刊物上发表超过200篇论文,总被引用超过16000次。拥有多个太阳能和微电机等方面的专利。在国际会议上和著名科研机构做邀请报告50多次,并曾组织多场国际会议。更多信息:http://mse.berkeley.edu/~jwu/

报告题目:VO2: New Physics and New Applications

时间15:00-16:00 pm, June 17th, 2017

地点强度楼二楼210会议室

摘要: Vanadium dioxide (VO2) has been a model quantum material system to study strongly correlation electron physics due to its metal-insulator phase transition coupled with a structural transition that occurs at 341K. In this talk, I will discuss our recent efforts in exploring exotic physics and novel applications of VO2: 1) violation of the Wiedemann-Franz where the electronic contribution to thermal conductivity is much less than what is expected from a Fermi liquid behavior; and 2) a reconfigurable meta-canvas on which arbitrary meta-photonic devices can be written, erased and re-written. Specifically, in electrically conductive solids, the Wiedemann-Franz law requires the electronic contribution to thermal conductivity to be proportional to electrical conductivity. We discover an order of magnitude breakdown of the Wiedemann-Franz law at high temperatures ranging from 240 to 341 K in metallic vanadium dioxide in the vicinity of its metal-insulator transition. Different from previously established mechanisms, the unusually low electronic thermal conductivity is a signature of the absence of quasiparticles in a strongly correlated electron fluid where heat and charge diffuse independently. For the novel application of developing a meta-canvas, we present an all-solid, rewritable meta-canvas on which nearly arbitrary photonic devices can be rapidly and repeatedly written and erased. Using the meta-canvas, we demonstrate dynamic manipulation of optical waves for light propagation, polarization and reconstruction. The meta-canvas supports physical (re)compilation of photonic operators akin to that of field-programmable gate arrays, opening up possibilities where photonic elements can be field-programmed to deliver complex, system-level functionalities.

新学期新气象,材料学人从未离开,上下求索的科研征程,怎能没有你?

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