The tuning of para- and diamagnetic cavity photon excitations in a square array of quantum dots in a magnetic field

TL;DR

This paper investigates how para- and diamagnetic photon excitations can be tuned in a quantum dot array within a cavity under a magnetic field, revealing controllable resonance peaks and breaking the Kohn theorem conditions.

Contribution

It introduces a real-time excitation scheme that leverages lattice symmetry and cavity interactions to control electron-photon resonances in quantum dot arrays.

Findings

Resonance peaks can be steered by excitation pulse parameters.

The method breaks the generalized Kohn theorem conditions.

Provides insights into the subband structure of the electron system.

Abstract

We employ a ``real-time'' excitation scheme to calculate the excitation spectra of a two-dimensional electron system in a square array of quantum dots placed in a circular cylindrical far-infrared photon cavity subjected to a perpendicular homogeneous external magnetic field. The Coulomb interaction of the electrons is handled via spin density functional theory and the para- and the diamagnetic parts of the electron-photon coupling are updated according to a configuration interaction method in each iteration of the density functional calculation. The results show that an excitation scheme built on using the symmetry of the lateral square superlattice of the dots and the cylindrical cavity produces both para- and diamagnetic resonance peaks with oscillator strengths that can be steered by the excitation pulse parameters. The excitation method breaks the conditions for the generalized Kohn theorem and allows for insight into the subband structure of the electron system and can be used both in and outside the linear response regime.