发布日期 2017-09-09【讲座】

Seminar on Quantum Devices Ⅰ

  

Supersymmetry in Closed Chains of Interacting Majorana Modes  

Zhao Huang (黄钊)

 

Research and Education Center for Natural Sciences,

Keio University, Kanagawa, Japan

 

 

Time3:00 pm, September 15, 2017

时间:2017915日(周五)下午300

PlaceRoom 2111, #2 Science Building, Peking University

地点:北京大学理科二号楼2111会议室

 

We consider a closed chain of even number of Majorana zero modes with nearest-neighbour couplings which are different site by site generically, thus no any crystal symmetry. Instead, we demonstrate the possibility of an emergent supersymmetry (SUSY), which is accompanied by gapless Fermionic excitations. In particular, the condition can be easily satisfied by tuning only one coupling, regardless of how many other couplings are there. Such a system can be realized by four Majorana modes on two parallel Majorana nanowires with their ends connected by Josephson junctions and bodies connected by an external superconducting ring. By tuning the Josephson couplings with a magnetic flux Φ through the ring, we get the gapless excitations at  with , which is signaled by a zero-bias conductance peak in tunneling conductance. We find this  generally a fractional number and oscillating with increasing Zeeman fields that parallel to the nanowires, which provide a unique experimental signature for the existence of Majorana modes (arXiv: 1707.04195).

 

 

SpeakerZhao Huang, obtained Ph.D. in National Institute for Matierals Science (NIMS) & University of Tsukuba in 2016. He is now working as a postdoc in Keio Univ. The research topics are condensed matter theory, mainly focusing on multiband superconductivity, topological superconductivity and other topological matter.

 

黄钊,2016年日本物质材料研究机构&筑波大学获得博士学位,2016年至今在庆应义塾大学做博士后。研究领域为凝聚态理论,研究兴趣主要是多带超导,拓扑超导和其他一些拓扑材料。

北京大学电子学系物理电子学研究所