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

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: AMISO(T ) = X/ sinh(X), where X = 2π 2 kT δf and δf 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.

Strong Interminivalley Scattering in Twisted Bilayer Graphene Revealed by High-Temperature Magneto-Oscillations

“…Taken together, the high-T character, peculiar frequency, and fragile phase identify these oscillations as an SA TBG analog of magneto-intersubband oscillations (MISO) discovered in wide quantum wells (QW) and studied in related systems [24][25][26][27][28][29][30][31][32]. In QW, the oscillations emerge when a two-dimensional electron system (2DES) occupies two or more energy bands capable of electron exchange [24][25][26][27]32].…”

Strong interminivalley scattering in twisted bilayer graphene revealed by high-temperature magnetooscillations

“…Taken together, the high-T character, peculiar frequency, and fragile phase identify these oscillations as an SA-TBG analogue of magneto-intersubband oscillations (MISO) discovered in wide quantum wells (QW) and studied in related systems. [23][24][25][26][27][28][29][30][31] In QW, the oscillations emerge when a two-dimensional electron system (2DES) occupies two or more energy bands capable of electron exchange. [23][24][25][26]31 In particular, when the LLs from different subbands become aligned within the thermal window around the Fermi level, elastic interband scattering gives rise to excess resistivity.…”