Thermal interferometry of anyons

TL;DR

This paper extends anyonic interferometry to neutral anyons, demonstrating how thermal currents in interferometers reveal topological order and quasiparticle statistics in topologically ordered systems.

Contribution

It introduces a method to detect topological order via thermal interferometry for neutral anyons, including non-Abelian types, and analyzes heat current signatures in different interferometer setups.

Findings

Thermal current varies with topological order in Fabry-Pérot interferometers.

Mach-Zehnder interferometers show interference only in topologically trivial systems.

Thermal current scaling at low temperatures reveals topological order.

Abstract

Anyonic interferometry probes the braiding phases of excitations in topologically ordered matter. This technique is well established for charged quasiparticles in the fractional quantum Hall effect. We propose to extend it to neutral anyons, such as Ising anyons in Kitaev magnets and quasiparticles in other neutral spin liquids. We find that the thermal current through an interferometer is sensitive to the statistics of tunneling quasiparticles. We present a systematic investigation of signatures of various Abelian and non-Abelian topological orders in Fabry-P\'erot and Mach-Zehnder interferometers. The heat current through a Fabry-P\'erot device is different for different topological orders and depends on the topological charge inside the interferometer. A Mach-Zehnder device shows interference in topologically trivial systems only. For a non-trivial statistics, the heat current reduces to the sum of the contributions from two constrictions in the interferometer. Furthermore, we identify another probe of topological order that involves the scaling of the thermal current through a single tunneling contact at low temperatures. The current shows a universal temperature dependence, sensitive to the topological order in the system.