Non-equilibrium fractional quantum Hall states visualized by optically detected MRI

TL;DR

This paper demonstrates real-space visualization of non-equilibrium fractional quantum Hall states using optically detected MRI, revealing stripe-like regions with topological protection and bidirectional nuclear polarization.

Contribution

It introduces a novel optical MRI technique to directly image and analyze non-equilibrium FQH states and their associated nuclear spin polarization.

Findings

Stripe-like excited states form under current excitation.

Regions are topologically protected and deformable.

Bidirectional nuclear polarization occurs at boundaries.

Abstract

Using photoluminescence microscopy enhanced by MRI, we visualize in real space both electron and nuclear polarization occurring in non-equilibrium FQH liquids. We observe stripe-like regions comprising FQH excited states which discretely form when the FQH liquid is excited by a source-drain current. These regions are topologically protected and deformable, and give rise to bidirectionally polarized nuclear spins as spin-resolved electrons flow across their boundaries.