Shear Bernstein modes in a two-dimensional electron liquid

TL;DR

This paper investigates shear Bernstein modes in a two-dimensional electron liquid, revealing their formation from quasiparticle interactions and their potential use in spectroscopic analysis of electron interactions.

Contribution

It introduces a new type of Bernstein modes arising from coupling with shear magnetosound waves in 2D electron liquids, and analyzes their spectrum across interaction regimes.

Findings

Bernstein modes originate from coupling with shear magnetosound waves.

Spectrum reconstruction observed across interaction strength.

Modes are sensitive probes for Landau interaction function.

Abstract

Bernstein modes are formed as a result of non-local coupling of collective excitations and cyclotron harmonics in magnetized plasma. In degenerate solid state plasma they are typically associated with magnetoplasmons. A different type of Bernstein modes arises in two-dimensional electron liquid at sufficiently strong quasiparticle interaction. We consider Bernstein modes originating from coupling between quasiparticle cyclotron harmonics and shear magnetosound waves. The latter may be responsible for the giant peak in radio-frequency photoresistance observed in high-quality GaAs quantum wells. Using Landau-Silin kinetic equation with an arbitrary strength of the interparticle Landau interaction, we trace the reconstruction of Bernstein mode spectrum in high-quality 2D electron systems across the crossover between weakly interacting degenerate electron gas and the correlated electron liquid. Sensitivity of Bernstein modes to the strength of quasiparticle interaction allows one to use them for spectroscopy of Landau interaction function in the electron Fermi liquids.