Thermoelectric Effect in the Normal Conductor-Superconductor Junction: A BTK Approach
M.M. Wysokiński
Marian Smoluchowski Institute of Physics, Jagiellonian University, W.S. Reymonta 4, 30-059 Kraków, Poland
Received: August 17, 2012
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The thermopower of the junction between normal conductor and s-wave superconductor has been investigated. For this purpose we have analyzed in detail a simple generalization of the Blonder-Tinkham-Klapwijk theory by taking into account explicitly an energy dependence of the density of states near the Fermi level. Both linear and nonlinear thermopowers have been calculated for 3D free electron gas, 3D Fermi liquid, and the case with Van Hove singularity in the vicinity of the Fermi level. In the linear regime, for all models, the thermopower as function of temperature has a clear maximum with its position and the value depending strongly on the junction barrier strength. In the nonlinear regime, we have found very large values of the thermopower (up to 8 kB/e) and strongly asymmetric behavior with respect to the change of the temperature gradient sign.
DOI: 10.12693/APhysPolA.122.758
PACS numbers: 74.45.+c, 74.25.fg, 73.23.Ad