Quantum geometry and magnon Hall transport in an altermagnet

TL;DR

This paper explores how quantum geometry influences magnon Hall transport in a 2D altermagnet, deriving an analytic expression for the quantum geometric tensor and linking conductivities to the altermagnetic parameter.

Contribution

It introduces an analytic formula for the quantum geometric tensor in bosonic systems and connects magnon transport properties to altermagnetism, offering new experimental insights.

Findings

Magnon Hall and Nernst conductivities depend on the altermagnetic parameter.

Derived an explicit analytic expression for the quantum geometric tensor.

Provides a potential experimental probe for altermagnetism.

Abstract

We compute magnon Hall conductivities in a minimal model of a two-dimensional altermagnet. To do so, we derive an analytic expression for the relevant quantum geometric tensor describing two-band bosonic Bogoliubov Hamiltonians, providing insight into the geometric, topological, and transport properties. The magnon thermal Hall and spin Nernst conductivities are shown to directly depend on the altermagnetic parameter, which may serve as an experimental probe of altermagnetism.