Edge-Induced Qubit Polarization in Systems with Ising Anyons

TL;DR

This paper explores how Fabry-Pérot interferometry in Ising anyon systems can inadvertently stabilize and polarize topological qubits through edge-bulk interactions, impacting quantum Hall experiments.

Contribution

It demonstrates that interferometry can stabilize and polarize topological qubits via edge-bulk interactions, providing insights into recent fractional quantum Hall experiments.

Findings

Interferometry stabilizes the topological qubit state.

Edge-bulk interactions can polarize the qubit.

Relevance to 5/2 fractional quantum Hall experiments.

Abstract

We investigate the proposed experimental setup for measuring the topological charge in a an Ising anyon system by means of Fabry-P\'erot interferometry with a chiral edge state. We show that such an interferometer has the unintended but not necessarily unwelcome effect of stabilizing the state of the system being measured (i.e., a topological qubit). We show further that interactions between the edge mode and the localized bulk quasiparticles can have the effect of polarizing the qubit, stabilizing its state. We discuss the these results in the context of recent interferometer experiments in the 5/2 fractional quantum Hall state, where the first of these effects is small, but the second may be relevant to the observed phenomena.