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

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, $\hbarω_γ / \hbarω_c$, between the photon energy, $\hbarω_γ$, and the cyclotron energy, $\hbarω_c$. Enhancement in the electron transport with increasing electron-photon coupling is observed when $\hbarω_γ / \hbarω_c > 1$. 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 $\hbarω_γ / \hbarω_c < 1$, as the external magnetic field causes circular confinement of the charge density around the dot.

8 pages, 8 figures