Magnetoresistance oscillations in multilayer systems - triple quantum wells

TL;DR

This paper investigates magnetoresistance oscillations in triple quantum well systems, revealing complex superpositions of oscillations and their interaction with microwave irradiation, supported by experimental and theoretical analysis.

Contribution

It extends the understanding of magneto-intersubband oscillations from two to three subbands and develops a general theory applicable to multiple subband systems.

Findings

Superposition of multiple MIS oscillations in triple quantum wells

Interference between MIS and microwave-induced resistance oscillations

Validation of inelastic mechanism for microwave photoresistance

Abstract

Magnetoresistance of two-dimensional electron systems with several occupied subbands oscillates owing to periodic modulation of the probability of intersubband transitions by the quantizing magnetic field. In addition to previous investigations of these magneto-intersubband (MIS) oscillations in two-subband systems, we report on both experimental and theoretical studies of such a phenomenon in three-subband systems realized in triple quantum wells. We show that the presence of more than two subbands leads to a qualitatively different MIS oscillation picture, described as a superposition of several oscillating contributions. Under a continuous microwave irradiation, the magnetoresistance of triple-well systems exhibits an interference of MIS oscillations and microwaveinduced resistance oscillations. The theory explaining these phenomena is presented in the general form, valid for an arbitrary number of subbands. A comparison of theory and experiment allows us to extract temperature dependence of quantum lifetime of electrons and to confirm the applicability of the inelastic mechanism of microwave photoresistance for the description of magnetotransport in multilayer systems.