Nonlinear Thermoelectricity with ElectronHole Symmetric Systems
Abstract
In the linear regime, thermoelectric effects between two conductors are possible only in the presence of an explicit breaking of the electronhole symmetry. We consider a tunnel junction between two electrodes and show that this condition is no longer required outside the linear regime. In particular, we demonstrate that a thermally biased junction can display an absolute negative conductance, and hence thermoelectric power, at a small but finite voltage bias, provided that the density of states of one of the electrodes is gapped and the other is monotonically decreasing. We consider a prototype system that fulfills these requirements, namely, a tunnel junction between two different superconductors where the Josephson contribution is suppressed. We discuss this nonlinear thermoelectric effect based on the spontaneous breaking of electronhole symmetry in the system, characterize its main figures of merit, and discuss some possible applications.
 Publication:

Physical Review Letters
 Pub Date:
 March 2020
 DOI:
 10.1103/PhysRevLett.124.106801
 arXiv:
 arXiv:1909.04590
 Bibcode:
 2020PhRvL.124j6801M
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Statistical Mechanics;
 Condensed Matter  Superconductivity
 EPrint:
 biblio information updated