Thermally activated intersubband scattering and oscillating magnetoresistance in quantum wells

TL;DR

This paper investigates magnetoresistance oscillations in high-mobility quantum wells, revealing thermally activated intersubband scattering effects that produce oscillations with distinct temperature sensitivities, supported by theoretical analysis.

Contribution

It introduces the observation of thermally activated intersubband scattering causing oscillations in magnetoresistance, with a theoretical model explaining these phenomena.

Findings

Oscillations appear at temperatures around 10 K.

Small-period oscillations are less thermally suppressed.

Theoretical model aligns with experimental results.

Abstract

Experimental studies of magnetoresistance in high-mobility wide quantum wells reveal oscillations which appear with an increase in temperature to 10 K and whose period is close to that of Shubnikov-de Haas oscillations. The observed phenomenon is identified as magnetointersubband oscillations caused by the scattering of electrons between two occupied subbands and the third subband which becomes occupied as a result of thermal activation. These small-period oscillations are less sensitive to thermal suppression than the largeperiod magnetointersubband oscillations caused by the scattering between the first and the second subbands. Theoretical study, based on consideration of electron scattering near the edge of the third subband, gives a reasonable explanation of our experimental findings.