Quantum magneto-electrodynamics of electrons embedded in a photon cavity

TL;DR

This paper explores the interaction between quantized electromagnetic fields and electrons in nanostructures within a magnetic field, highlighting the limits of common models and the impact of strong coupling on charge distribution.

Contribution

It provides a detailed numerical analysis of electron-photon interactions, emphasizing the importance of geometry, polarization, and strong coupling effects beyond traditional models.

Findings

Two-level system and Jaynes-Cummings model valid in weak coupling

Quadratic vector potential causes significant spectral corrections in strong coupling

Strong cavity photon mode polarizes charge distribution requiring extensive basis states

Abstract

We investigate the coupling between a quantized electromagnetic field in a cavity resonator and a Coulomb interacting electronic system in a nanostructure in an external magnetic field. Effects caused by the geometry of the electronic system and the polarization of the electromagnetic field are explicitly taken into account. Our numerical results demonstrate that the two-level system approximation and the Jaynes-Cummings model remain valid in the weak electron-photon coupling regime, while the quadratic vector potential in the diamagnetic part of the charge current leads to significant correction to the energy spectrum in the strong coupling regime. Furthermore, we find that a coupling to a strong cavity photon mode polarizes the charge distribution of the system requiring a large basis of single-electron eigenstates to be included in the model.