Magnetospectroscopy of symmetric and anti-symmetric states in double quantum wells

TL;DR

This study investigates magneto-transport phenomena in double quantum wells, revealing beating effects in SdH oscillations and proposing a model with separate quasi-Fermi levels for symmetric and anti-symmetric states.

Contribution

It introduces a new approach to calculating Landau levels in DQWs and explains magneto-transport effects using separate quasi-Fermi levels for different symmetry states.

Findings

Beating effect observed in SdH oscillations at low temperatures.

Development of a Landau level energy calculation method for DQWs.

Proposal of two distinct quasi-Fermi levels for symmetric and anti-symmetric states.

Abstract

The experimental results obtained for the magneto-transport in the InGaAs/InAlAs double quantum wells (DQW) structures of two different shapes of wells are reported. The beating-effect occurred in the Shubnikov-de Haas (SdH) oscillations was observed for both types of the structures at low temperatures in the parallel transport when magnetic field was perpendicular to the layers. An approach to the calculation of the Landau levels energies for DQW structures was developed and then applied to the analysis and interpretation of the experimental data related to the beating-effect. We also argue that in order to account for the observed magneto-transport phenomena (SdH and Integer Quantum Hall effect), one should introduce two different quasi-Fermi levels characterizing two electron sub-systems regarding symmetry properties of their states, symmetric and anti-symmetric ones which are not mixed by electron-electron interaction.