A coherent double-quantum-dot electron pump

TL;DR

This paper studies an electron pump made of an asymmetric double quantum dot under electromagnetic radiation, analyzing how its transport properties depend on quantum tunneling mechanisms and radiation frequency.

Contribution

It provides a detailed analysis of coherent and incoherent tunneling processes in a double quantum dot electron pump under radiation.

Findings

Transport can be controlled by radiation frequency.

Resonant tunneling peaks are identified in the pumping current.

Both sequential and co-tunneling mechanisms are characterized.

Abstract

We have investigated the transport characteristics of an electron pump consisting of an asymmetric double quantum dot at zero bias voltage which is subject to electromagnetic radiation. Depending on the energies of the intermediate states in the pumping cycle, electrons can be transferred through the dots incoherently via sequential tunneling or coherently via co-tunneling. The dc transport through the system can be controlled by the frequency of the applied radiation. We concentrate on resonant tunneling peaks in the pumping current that are interesting to observe experimentally.