Competition of static magnetic and dynamic photon forces in electronic transport through a quantum dot

TL;DR

This paper theoretically examines how static magnetic and dynamic photon forces influence electron transport in a quantum dot within a photon cavity, revealing how their interplay affects transport efficiency based on energy ratios.

Contribution

It introduces a detailed analysis of the competition between magnetic and photon forces in quantum dot transport, highlighting the effects of photon energy to cyclotron energy ratio on electron flow.

Findings

Transport enhancement occurs when photon energy exceeds cyclotron energy.

Photon field extends charge distribution towards leads, increasing conductance.

Magnetic confinement suppresses electron transport when photon energy is lower.

Abstract

We investigate theoretically the balance of the static magnetic and the dynamical photon forces in the electron transport through a quantum dot in a photon cavity with a single photon mode. The quantum dot system is connected to external leads and the total system is exposed to a static perpendicular magnetic field. We explore the transport characteristics through the system by tuning the ratio, $\hbar\omega_{\gamma} / \hbar\omega_c$, between the photon energy, $\hbar\omega_{\gamma}$, and the cyclotron energy, $\hbar\omega_c$. Enhancement in the electron transport with increasing electron-photon coupling is observed when $\hbar\omega_{\gamma} / \hbar\omega_c > 1$. In this case the photon field dominates and stretches the electron charge distribution in the quantum dot, extending it towards the contacts area for the leads. Suppression in the electron transport is found when $\hbar\omega_{\gamma} / \hbar\omega_c < 1$, as the external magnetic field causes circular confinement of the charge density around the dot.