# Topological thermal Hall effect of "magnetic monopoles" in pyrochlore U(1) spin liquid

## TL;DR

This paper predicts a topological thermal Hall effect caused by magnetic monopoles in pyrochlore U(1) spin liquids, providing a potential experimental signature of emergent gauge fields and monopole-gauge coupling.

## Contribution

It introduces a novel prediction of TTHE due to magnetic monopoles in pyrochlore U(1) spin liquids, linking emergent gauge flux to observable thermal transport.

## Key findings

- Prediction of TTHE as evidence of monopole-gauge coupling
- Emergent dual U(1) gauge flux induces Lorentz force on monopoles
- Applicability to various pyrochlore spin liquid materials

## Abstract

"Magnetic monopole" is an exotic quantum excitation in pyrochlore U(1) spin liquid, and its emergence is purely of quantum origin and has no classical analogue. We predict topological thermal Hall effect (TTHE) of "magnetic monopoles" and present this prediction through non-Kramers doublets. We observe that, when the external magnetic field polarizes the Ising component of the local moment, internally this corresponds to the induction of emergent dual U(1) gauge flux for the "magnetic monopoles". The motion of "magnetic monopoles" is then twisted by the induced dual gauge flux. This emergent Lorentz force on "magnetic monopoles" is the fundamental origin of TTHE. Therefore, TTHE would be a direct evidence of the "monopole"-gauge coupling and the emergent U(1) gauge structure in pyrochlore U(1) spin liquid. Our result does not depend strongly on our choice of non-Kramers doublets for our presentation, and can be well extended to Kramers doublets. Our prediction can be readily tested among the pyrochlore spin liquid candidate materials. We give a detailed discussion about the expectation for different pyrochlore magnets.