主讲人：陈川 博士（清华大学）

题目：Zeeman induced vison motion in the Kitaev honeycomb model

时间：2023年10月30日（周一）下午15：00

地点：理工楼1226

联系人：么志远

报告摘要：

The Kitaev honeycomb model hosts a fascinating fractionalized state of matter featuring emergent Majorana fermions and a vison particle that carries the flux of an emergent gauge field. In the exactly solvable model these visons are static, but certain perturbations can induce their motion. Utilizing a recently developed duality mapping method, we show that the vison motion induced by a Zeeman field is sharply distinct in the ferromagnetic vs the antiferromagnetic Kitaev models. Namely, in the ferromagnetic model the vison has a trivial nonprojective translational symmetry, whereas in the antiferromagnetic Kitaev model it has a projective translational symmetry with $\pi$ flux per unit cell. The vison band of the ferromagnetic case has zero Berry curvature and no associated intrinsic contribution to the thermal Hall effect. In contrast, in the antiferromagnetic case there are two gapped vison bands with opposite Chern numbers and an associated intrinsic vison contribution to the thermal Hall effect. We have also studied the braiding phase of visons in the Ising topologically ordered state and find good agreement with existing theories.

个人简介：

陈川，清华大学高等研究院博士后。2014年本科毕业于四川大学，2018年博士毕业于新加坡国立大学，随后在德国马普学会复杂物理系统研究所及清华大学高等研究院从事博士后工作。主要研究方向涉及二维材料中的电荷密度波与超导，量子自旋液体，高温超导体等。