Orbital angular momentum in a topological superconductor with Chern number higher than $1$

TL;DR

This paper studies the bulk orbital angular momentum in a two-dimensional topological superconductor with Chern number -3, revealing how edge states and spin-orbit interactions influence angular momentum properties across topological phases.

Contribution

It provides a detailed analysis of orbital angular momentum behavior in a high Chern number topological superconductor, highlighting the effects of spin-orbit interactions and edge states.

Findings

Orbital angular momentum per particle is reduced by edge states in the topological phase.

The reduction of L_z/N depends on the strength of spin-orbit interactions.

L_z/N exhibits discontinuous or continuous behavior at the phase transition depending on SOI strength.

Abstract

We investigate the bulk orbital angular momentum (AM) in a two-dimensional hole-doped topological superconductor (SC) which is composed of a hole-doped semiconductor thin film, a magnetic insulator, and an $s$-wave SC and is characterized by the Chern number $C = -3$. In the topological phase, $L_z/N$ is strongly reduced from the intrinsic value by the non-particle-hole-symmetric edge states as in the corresponding chiral $f$-wave SCs when the spin-orbit interactions (SOIs) are small, while this reduction of $L_z/N$ does not work for the large SOIs. Here $L_z$ and $N$ are the bulk orbital AM and the total number of particles at zero temperature, respectively. As a result, $L_z/N$ is discontinuous or continuous at the topological phase transition depending on the strengths of the SOIs. We also discuss the effects of the edge states by calculating the radial distributions of the orbital AM.