Interplay of Kondo and superconductivity in the presence of spin-orbital coupling
发布日期：2021-05-07
作者：
编辑：
来源：兰州理论物理中心
主讲人：李林 副研究员（四川师范大学）
题目：Interplay of Kondo and superconductivity in the presence of spin-orbital coupling
时间：2021年5月8日（周六）下午16:50
地点：理工楼1226报告厅
联系人：罗洪刚
摘要：The Kondo effect is one of the well-understood many-body phenomena in condensed-matter physics. In recent decades, the Kondo effect in a quantum dot (QD), manifested as a zero-bias resonance peak, has been intensively investigated due to the high controllability. In a QD coupled with an s-wave superconductor, the Kondo resonance is significantly suppressed due to the superconducting energy gap, and the low-energy transport is mainly determined by the behaviors of the spin-induced YuShiba-Rusinov (YSR) state. The competition between the Kondo effect and the superconducting pairing interaction in a hybrid superconductor-QD device generates two different ground states, namely, the magnetic doublet and the Kondo singlet state. The quantum phase transition (QPT) between these two ground states takes place at TK/△~1, which is indicated by the level-crossing behavior of the YSR state. In the presence of Rashba spin-orbit coupling (RSOC), however, the phase boundary of the ground states depends on the strength of the RSOC rather than TK/△~1 [1]. The underlying physics is the Kondo screening contributed from the spin-triplet states[2]. The deviation of the critical point from TK/△~1 is a universal phenomenon in the presence of spin-orbital coupling [3].
References：
[1]Lin Li, Ming-Xin Gao, Zhen-Hua Wang, Hong-Gang Luo, and Wei-Qiang Chen, Phys. Rev. B 97, 064519 (2018).
[2]Lin Li, Jin-Hua Sun, Wei Su, Zhen-Hua Wang, Dong-Hui Xu, Hong-Gang Luo, and Wei-Qiang Chen, Phys. Rev. B 103, 125144 (2021).
[3]Yu Zhang, Lin Li, Jin-Hua Sun, Dong-Hui Xu, Rong Lü, Hong-Gang Luo, and Wei-Qiang Chen, Phys. Rev. B 101, 035124 (2020).
个人简介：
李林，四川师范大学副研究员，2006年毕业于中国矿业大学建筑环境与设备工程获得学士学位，2006-2012年在兰州大学获得粒子物理与原子核硕士学位与理论物理博士学位，2012-2018年先后再香港大学物理系与南方科技大学从事博士后、助理研究员、研究助理教授等工作。近年来主要研究介观量子体系中超导与近藤效应的相互作用问题，在PRB、New. J. Phys.等国际权威学术刊物上发表学术论文20余篇，主持国家自然科学基金理论物理专款与青年项目各1项、广东省与四川省自然科学基金项目各1项，2014年获得深圳市孔雀计划B类、2019年获得四川省青年千人计划资助。
