From the Aharonov-Bohm effect to Peltier-cooling in mesoscopic devices

Tuesday 25 May 2010 at 4pm

CNRS Bât E, conference room "Louis Weil" on 3rd floor

Robert S Whitney(Institut Laue-Langevin, Grenoble)

 

The electronic transport properties of nanoscale devices at are strongly affected by the quantum coherence of the electrons. However interference effects can also cause finite thermoelectric effects; a heat-difference can induce a voltage-difference (Seebeck effect) and vice-versa (Peltier cooling). Using an Aharonov-Bohm interferometer as a toy model, I show how interference can induces such effects.

I then turn to the more subtle interference effects in quantum dots coupled to superconductors, where Andreev reflection strongly magnifies these effects. I review our theory (Jacquod and Whitney, arXiv:0910.294) which shows that the average Seebeck effect is odd in the magnetic flux threading the device. However in devices where the average is zero, the effect is dominated by mesoscopic fluctuations which are even in the flux.

We argue that this is the first theory which potentially explains all experiments on thermoelectric effects in such devices.

Chandrasekhar and co-workers PRL 81, 437(1998); Nature Physics 5, 393 (2009), and Petrashov and co-workers PRB 67, 140502(R) (2003).

 

Download the abstract