Manifestation of the magnetic depopulation of one-dimensional subbands in the optical absorption of acoustic magnetoplasmons in side-gated quantum wires

TL;DR

This study explores how magnetic depopulation of 1D subbands affects the optical absorption of acoustic magnetoplasmons in side-gated quantum wires, revealing oscillations linked to the screened density profile.

Contribution

It provides experimental and theoretical insights into the magnetic depopulation effects on acoustic magnetoplasmons in quantum wires, overcoming Kohn's theorem through double-layered structures.

Findings

Oscillations in magnetic-field dispersion of acoustic plasmons.

Dependence of oscillations on magnetic depopulation of subbands.

Self-consistent screening influences the observed phenomena.

Abstract

We have investigated experimentally and theoretically the far-infrared (FIR) absorption of gated, deep-mesa-etched GaAs/Al$_x$Ga$_{1-x}$As quantum wires. To overcome Kohn's theorem we have in particular prepared double-layered wires and studied the acoustic magnetoplasmon branch. We find oscillations in the magnetic-field dispersion of the acoustic plasmon which are traced back to the self-consistently screened density profile in its dependence on the magnetic depopulation of the one-dimensional subbands.