题目：半导体线拓扑超导体中的约瑟夫森效应研究

报告人：刘杰 副教授

                 西安交通大学理学院

时间：2018年4月4日上午10:00

地点：国家脉冲强磁场科学中心C204

报告摘要：

The 4π-periodic Josephson effect is a distinguishing feature of a topological Josephson junction. However, stringent conditions make it hard to observe in experiments. In this work, we study the transient transport properties in a topological Josephson junction numerically. We show that the 4π Josephson current can be sustained under nonequilibrium conditions. The properties of the Josephson current are analyzed for different conditions and three main regimes are identified. First, when both the superconducting wires of the Josephson junction lie in the topologically nontrivial region, a 4π Josephson current can appear upon suddenly applying a dc voltage. Second, when one superconducting wire lies in the trivial region, while the other wire lies in the nontrivial region, the Josephson current is 2π periodic but the component of the higher-order Josephson current increases. Third, when both wires lie in the trivial region, a stable 2π Josephson current is observed. Most importantly, the fractional Josephson effect is fragile in the presence of disorder. Hence experiments should be designed carefully to eliminate the effect of disorder. These results could be helpful to optimize fine-tuning of the experimental parameters to observe the 4π-periodic Josephson current in a topological Josephson junction.

报告人简介：

刘杰：西安交通大学理学院副教授。2011年获中国科学院物理研究所物理学博士学位。2011至2014年于香港科技大学、香港大学从事博士后研究。2014年10月受聘为西安交通大学理学院副教授。目前主要研究方向为拓扑超导体中的输运性质。共发表PRL3篇（一作一篇，被引约200余次），PRB 13篇。

热忱欢迎广大老师，同学来聆听报告！