Inter-subband resistance oscillations in crossed electric and magnetic fields

TL;DR

This paper investigates quantum resistance oscillations in GaAs quantum wells under combined electric and magnetic fields, revealing different oscillation regimes and proposing a model based on subband energy variations.

Contribution

It introduces a model explaining inter-subband resistance oscillations as caused by electric current-induced energy separation variations, covering different magnetic field regimes.

Findings

Current-induced oscillations at low magnetic fields are Landau-Zener transitions.

High magnetic field oscillations have a period independent of magnetic field.

Oscillations are periodic in inverse magnetic field, unaffected by bias.

Abstract

Quantum oscillations of nonlinear resistance are investigated in response to electric current and magnetic field applied perpendicular to single GaAs quantum wells with two populated subbands. At small magnetic fields current-induced oscillations appear as Landau-Zener transitions between Landau levels inside the lowest subband. Period of these oscillations is proportional to the magnetic field. At high magnetic fields different kind of quantum oscillations emerges with a period,which is independent of the magnetic field. At a fixed current the oscillations are periodic in inverse magnetic field with a period that is independent of the dc bias. The proposed model considers these oscillations as a result of spatial variations of the energy separation between two subbands induced by the electric current.