The effects of a far-infrared photon cavity field on the magnetization of a square quantum dot array

TL;DR

This paper investigates how a far-infrared photon cavity field influences the magnetization of a quantum dot array in a GaAs heterostructure, revealing cavity-induced polarization effects and the formation of magnetoplasmon-polaritons.

Contribution

It adapts a gradient-based exchange-correlation functional within QEDFT to study cavity effects on a 2DEG quantum dot array, highlighting novel magnetization behaviors.

Findings

Cavity photon field polarizes electron charge distribution.

Orbital magnetization exhibits nontrivial changes due to cavity effects.

Formation of magnetoplasmon-polaritons around the Fermi energy.

Abstract

The orbital and spin magnetization of a cavity-embedded quantum dot array defined in a GaAs heterostructure are calculated within quantum-electrodynamical density-functional theory (QEDFT). To this end a gradient-based exchange-correlation functional recently employed for atomic systems is adapted to the hosting two-dimensional electron gas (2DEG) submitted to an external perpendicular homogeneous magnetic field. Numerical results reveal the polarizing effects of the cavity photon field on the electron charge distribution and nontrivial changes of the orbital magnetization. We discuss its intertwined dependence on the electron number in each dot, and on the electron-photon coupling strength. In particular, the calculated dispersion of the photon-dressed electron states around the Fermi energy as a function of the electron-photon coupling strength indicates the formation of magnetoplasmon-polaritons in the dots.