Zeeman Field-Tuned Transitions for Surface Chern Insulators

TL;DR

This paper explores how applying a Zeeman field to mirror symmetric surfaces of topological crystalline insulators induces transitions between surface insulating states with various Chern numbers, revealing a tunable topological phase diagram.

Contribution

It introduces a detailed analysis of Zeeman field-induced phase transitions and the resulting Chern number variations in topological crystalline insulator surfaces.

Findings

Zeeman field gaps surface states leading to quantized anomalous Hall effect.

Transitions between surface insulating states with Chern numbers from -4 to 4.

Phase boundaries form along great circles on a sphere in field orientation space.

Abstract

Mirror symmetric surfaces of a topological crystalline insulator host even number of Dirac surface states. A surface Zeeman field generically gaps these states leading to a quantized anomalous Hall effect. Varying the direction of Zeeman field induces transitions between different surface insulating states with any two Chern numbers between -4 and 4. In the crystal frame the phase boundaries occur for field orientations which are great circles with (111)-like normals on a sphere.