Title: Supersymmetry in Closed Chains of Interacting Majorana Modes.

Speaker: Dr. Zhao Huang (黄钊) Affliation: Research and Education Center for Natural Sciences, Keio University, Kanagawa, Japan 报告时间：2017年9月20日周三 14:00 报告地点：物理馆323报告厅.

Abstract: 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 $\Phi$ through the ring, we get the gapless excitations at $\Phi_{SUSY}=\pm f \Phi_0$ with $\Phi_0=hc/2e$, which is signaled by a zero-bias conductance peak in tunneling conductance. We find this $f$ 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..

Reference: arXiv: 1707.04195, Zhao Huang, Shinji Shimasaki, Muneto Nitta.

About the Speaker:

黄钊，2010年中国人民大学获得物理学士学位，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，包括多带超导，拓扑超导，拓扑绝缘体等，目前的主要研究兴趣为拓扑超导中马约拉纳费米子的性质和应用，超对称在凝聚态体系中的实现以及其他高能物理和凝聚态物理的交叉领域。.