Characterization of Bernstein modes in quantum dots

TL;DR

This paper investigates Bernstein modes in non-parabolic quantum dots, revealing their coupling with electron-hole excitations and the effects of potential non-quadratic terms on mode energy separation and local absorption patterns.

Contribution

It provides a detailed characterization of Bernstein modes in quantum dots, highlighting the influence of potential shape and magnetic field on mode coupling and energy distribution.

Findings

Bernstein modes couple with electron-hole excitations in quantum dots.

Non-quadratic potential terms cause energy separation between bulk and edge modes.

Local absorption patterns evolve with magnetic field, showing fragmented peaks.

Abstract

The dipole modes of non-parabolic quantum dots are studied by means of their current and density patterns as well as with their local absorption distribution. The anticrossing of the so-called Bernstein modes originates from the coupling with electron-hole excitations of the two Landau bands which are occupied at the corresponding magnetic fields. Non-quadratic terms in the potential cause an energy separation between bulk and edge current modes in the anticrossing region. On a local scale the fragmented peaks absorb energy in complementary spatial regions which evolve with the magnetic field.