Abstract
We analyze quantum charge pumping in an open ring with a dot embedded in one of its arms. We show that cyclic driving of the dot levels by a single parameter leads to a pumped current when a static magnetic flux is simultaneously applied to the ring. Based on the computation of the Floquet-Green’s functions, we show that for low driving frequencies , the interplay between the spatial interference through the ring plus photon-assisted tunneling gives an average direct current, which is proportional to . The direction of the pumped current can be reversed by changing the applied magnetic field.
- Received 6 September 2005
DOI:https://doi.org/10.1103/PhysRevB.72.245339
©2005 American Physical Society