Non-local transport properties of nanoscale conductor-microwave cavity systems

TL;DR

This paper theoretically explores how two spatially separated double quantum dots coupled to a microwave cavity exhibit non-local transport effects, photon-mediated correlations, and entanglement, advancing understanding of light-matter interactions at the quantum level.

Contribution

It introduces a generalized Tavis-Cummings model to analyze non-local transport and entanglement in nanoscale conductor-cavity systems, revealing new quantum phenomena.

Findings

Photon-mediated non-local current and correlations

Dynamical channel blockade lifted by photon emission

Large entanglement between electron orbital states

Abstract

Recent experimental progress in coupling nanoscale conductors to superconducting microwave cavities has opened up for transport investigations of the deep quantum limit of light-matter interactions, with tunneling electrons strongly coupled to individual cavity photons. We have investigated theoretically the most basic cavity-conductor system with strong, single photon induced non-local transport effects; two spatially separated double quantum dots (DQD:s) resonantly coupled to the fundamental cavity mode. The system, described by a generalized Tavis-Cummings model, is investigated within a quantum master equation formalism, allowing us to account for both the electronic transport properties through the DQD:s as well as the coherent, non-equilibrium cavity photon state. We find sizeable non-locally induced current and current cross-correlations mediated by individual photons. From a full statistical description of the electron transport we further reveal a dynamical channel blockade in one DQD lifted by photon emission due to tunneling through the other DQD. Moreover, large entanglement between the orbital states of electrons in the two DQD:s is found for small DQD-lead temperatures.