Nonlocal transport properties of nanoscale conductor–microwave cavity systems

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.

Thermoelectric energy harvesting with quantum dots

“…figure 18. Such hybrid structures that allow the investigation the interplay of light and matter at the nansocale have recently gained a lot of interest both theoretically [167,168,169,170,171,172,173,174,175,176,177] as well as experimentally [178,179,180,181,182,183,184,185,186] in the context of circuit quantum electrodynamics. Similar to the previously discussed energy harvester, the hybrid microwave cavity heat engine [57] also allows to separate the hot and the cold part of the engine by a macroscopic distance of the order of a centimeter.…”

Lasing in circuit quantum electrodynamics with strong noise

“…Here an applied transport voltage drives a current through a double dot, where the energy difference between left and right dot can be used to create photons. The correlation of photon emission and transport properties has been extensively studied [20][21][22][23]. It has also been theoretically shown that lasing can be achieved [20,24].…”

Coupling Two Distant Double Quantum Dots with a Microwave Resonator

“…When sweeping the detuning of each DQD, in the proximity of the charge-degeneracy points, a dip is observed in the resonator reflection amplitude due to nonadditive dispersive contributions from the two DQDs. This phenomenon is explained by the Tavis-Cummings model 8 , and it demonstrates the simultaneous dispersive coupling between one photonic mode and two DQDs. Moreover, with finite-bias voltages, the current through one of the DQDs is affected by the current through the other.…”