Temperature Damping of Magneto-Intersubband Resistance Oscillations in Magnetically Entangled Subbands

TL;DR

This study investigates how temperature affects magneto-intersubband resistance oscillations in GaAs quantum wells, revealing a new suppression regime linked to magnetic entanglement between subbands and proposing a model that matches experimental data.

Contribution

The paper introduces a novel model explaining strong temperature damping of MISO due to magnetic entanglement, supported by experimental validation.

Findings

Temperature decreases MISO amplitude via Dingle factor at moderate tilts.

At large tilts, a new strong suppression regime emerges.

The proposed model accurately predicts the temperature damping factor.

Abstract

Magneto-intersubband resistance oscillations (MISO) of highly mobile 2D electrons in symmetric GaAs quantum wells with two populated subbands are studied in magnetic fields tilted from the normal to the 2D electron layer at different temperatures $T$. Decrease of MISO amplitude with temperature increase is observed. At moderate tilts the temperature decrease of MISO amplitude is consistent with decrease of Dingle factor due to reduction of quantum electron lifetime at high temperatures. At large tilts new regime of strong MISO suppression with the temperature is observed. Proposed model relates this suppression to magnetic entanglement between subbands, leading to beating in oscillating density of states. The model yields corresponding temperature damping factor: $A_{MISO}(T)=X/\sinh(X)$, where $X=2\pi^2kT\delta f$ and $\delta f$ is difference frequency of oscillations of density of states in two subbands. This factor is in agreement with experiment. Fermi liquid enhancement of MISO amplitude is observed.