关于举行日本理化学研究所何骏博士学术报告会的通知

发布时间:2021-12-28设置

报告题目:Optical Responses of Chiral Majorana Modes

报 告 人:何骏 博士 (日本理化学研究所)

主 持 人:刘涛 教授

报告时间:202214日(星期二)下午3:00

报告地点:物理楼(18号楼)二楼220会议室

欢迎广大师生参加。

  

  

物理与光电学院

20211228

  

  

报告摘要:

Majorana fermions exist on the boundaries of two-dimensional topological superconductors (TSCs) as charge-neutral quasiparticles. The neutrality makes the detection of such states challenging from both experimental and theoretical points of view. Current methods largely rely on transport measurements in which Majorana fermions manifest themselves by inducing electron-pair tunneling (Andreev reflection) at the lead-contacting point. In this talk, I will discuss alternative detecting methods --- by shining light.

I will show that chiral Majorana fermions in TSCs generate local optical responses. This results in a local optical conductivity σxx that is proportional to ω2 when the photon frequency ω is small [1]. The features of the σxx distinguish chiral Majorana fermions not only from trivial superconductors or insulators (where σxx=0), but also from normal fermion edge states such as those in quantum Hall systems (where σxx=e2/2h). Then we further discuss the optical responses of chiral Majorana modes in Kitaev model of quantum spin liquids (QSLs), where the optical signal can be detected locally by Raman spectroscopy [2] since the Raman scattering intensity is proportional to ω3, where ω is the Raman frequency shift.

  

参考文献:

[1] James Jun He, Yukio Tanaka, and Naoto Nagaosa, Phys. Rev. Lett. 126, 237002 (2021).

[2] James Jun He, and Naoto Nagaosa, Phys. Rev. B 103, L241109 (2021).

  

报告人简介:

何骏博士2017年毕业于香港科技大学物理系,师从K.T.Law教授。毕业后在日本理化学研究所(RIKEN)衍生物质科学研究中心(Center for Emergent Matter Science or CEMSNaoto Nagaosa研究组担任博士后研究员,从事凝聚态物理理论研究。主要研究物质的拓扑物态、自旋轨道耦合的电子系统、超导电系统等,具体方向包括拓扑超导与马约拉纳费米子、非中心对称的超导、约瑟夫森结、Ising超导体、超导二极管效应等。以(共同)第一作者在Physical Review Letters (3)Nature Communications(2)发表论文共5篇。在Physical Review BCommunications Physics等学术期刊发表论文共13篇。


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