Edge-Induced Qubit Polarization in Systems with Ising Anyons

Understand

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.