Evidence of inter-layer interaction in magneto-luminescence spectra of electron bilayers

TL;DR

This study investigates how inter-layer Coulomb interactions influence magneto-luminescence spectra in electron bilayers, revealing pseudospin polarization loss and excitonic correlations linked to quantum Hall states.

Contribution

It uncovers the role of inter-layer interactions in magneto-luminescence, highlighting the population of anti-symmetric levels due to excitonic effects in quantum Hall bilayers.

Findings

Magneto-luminescence spectra show maxima at filling factors 1 and 2/3.

Loss of pseudospin polarization linked to anti-symmetric level population.

Inter-layer Coulomb interactions significantly affect quantum Hall states.

Abstract

Magneto-luminescence studies in electron bilayers reveal the hallmarks of the even-denominator and other quantum Hall states in the intensities and energies of the inter-band optical recombination lines. In the presence of a small tunneling gap between the layers the magneto-optical emission from the lowest anti-symmetric subband, not populated in a single-electron picture, displays maxima at filling factors 1 and 2/3. These findings uncover a loss of pseudospin polarization, where the pseudospin describes the layer index degree of freedom, that is linked to an anomalous population of the anti-symmetric level due to excitonic correlations. The results demonstrate a new realm to probe the impact of inter-layer Coulomb interaction in quantum Hall bilayers.