Back-action effects in cavity-coupled quantum conductors

TL;DR

This paper investigates how photon-mediated interactions in a cavity influence electronic transport in distant quantum systems, revealing back-action effects, photon-assisted currents, and Rabi oscillations in transient and steady states.

Contribution

It introduces a detailed analysis of back-action effects and photon-mediated coupling in cavity-embedded quantum conductors using a master equation approach.

Findings

Photon-mediated coupling affects steady-state and transient currents.

Bias in one subsystem induces photon-assisted current in the other.

Transient currents exhibit Rabi oscillations depending on initial states.

Abstract

We study the electronic transport through a pair of distant nanosystems ($S_a$ and $S_b$) embedded in a single-mode cavity. Each system is connected to source and drain particle reservoirs and the electron-photon coupling is described by the Tavis-Cummings model. The generalized master equation approach provides the reduced density operator of the double-system in the dressed-states basis. It is shown that the photon-mediated coupling between the two subsystems leaves a signature on their transient and steady-state currents. In particular, a suitable bias applied on subsystem $S_b$ induces a photon-assisted current in the other subsystem $S_a$ which is otherwise in the Coulomb blockade. We also predict that a transient current passing through one subsystem triggers a charge transfer between the optically active levels of the second subsystem even if the latter is not connected to the leads. As a result of back-action, the transient current through the open system develops Rabi oscillations (ROs) whose period depends on the initial state of the closed system.