THERMOELECTRIC PROPERTIES OF MESOSCOPIC SUPERCONDUCTORS

We develop a general framework for describing thermoelectric effects i n phase-coherent superconducting structures. Formulas for the electric al conductance, thermal conductance, thermopower, and Peltier coeffici ent are obtained and their various symmetries discussed. Numerical res ults for both dirty and clean Andreev interferometers are presented. W e predict that giant oscillations of the thermal conductance can occur , even when oscillations in the electrical conductance are negligibly small. Results for clean, two-dimensional systems with a single superc onducting inclusion are also presented, which show that normal-state o scillations arising from quasiparticle boundary scattering are suppres sed by the onset of superconductivity. In contrast, for a clean system with no normal-state boundary scattering, switching on superconductiv ity induces oscillations in off-diagonal thermoelectric coefficients.