Cavity-photon contribution to the effective interaction of electrons in parallel quantum dots

TL;DR

This study investigates how a cavity photon mode influences electron interactions in parallel quantum dots, revealing increased repulsion and potential for charge polarization, with implications for quantum control.

Contribution

It demonstrates that cavity photons enhance electron-electron repulsion and induce charge polarization in double quantum dots, a novel insight into light-matter interaction effects.

Findings

Cavity photons increase electron-electron repulsion in quantum dots.

Photon dressing leads to charge delocalization and polarization.

External fields can modulate effective electron repulsion.

Abstract

A single cavity photon mode is expected to modify the Coulomb interaction of an electron system in the cavity. Here we investigate this phenomena in a parallel double quantum dot system. We explore properties of the closed system and the system after it has been opened up for electron transport. We show how results for both cases support the idea that the effective electron-electron interaction becomes more repulsive in the presence of a cavity photon field. This can be understood in terms of the cavity photons dressing the polarization terms in the effective mutual electron interaction leading to nontrivial delocalization or polarization of the charge in the double parallel dot potential. In addition, we find that the effective repulsion of the electrons can be reduced by quadrupolar collective oscillations excited by an external classical dipole electric field.