Semiclassical theory of a quantum pump
Abstract
In a quantum charge pump, the periodic variation of two parameters that affect the phase of the electronic wave function causes the flow of a direct current. The operating mechanism of a quantum pump is based on quantum interference, the phases of interfering amplitudes being modulated by the external parameters. In a ballistic quantum dot, there is a minimum time before which quantum interference cannot occur: the Ehrenfest time τE . Here we calculate the current pumped through a ballistic quantum dot if τE is comparable to the mean dwell time τD . Remarkably, we find that the pumped current has a component that is not suppressed if τE≫τD .
- Publication:
-
Physical Review B
- Pub Date:
- November 2006
- DOI:
- 10.1103/PhysRevB.74.205327
- arXiv:
- arXiv:cond-mat/0607425
- Bibcode:
- 2006PhRvB..74t5327R
- Keywords:
-
- 73.23.-b;
- 05.45.Mt;
- 73.50.Pz;
- Electronic transport in mesoscopic systems;
- Quantum chaos;
- semiclassical methods;
- Photoconduction and photovoltaic effects;
- Condensed Matter - Mesoscopic Systems and Quantum Hall Effect
- E-Print:
- 14 pages, 8 figures. Revised version, minor changes