Thermopower and thermophase in a d -wave superconductor
Artikel i vetenskaplig tidskrift, 2022

In an unconventional superconductor, the interplay of scattering off impurities and Andreev processes may lead to different scattering times for electronlike and holelike quasiparticles. Such electron-hole asymmetry appears when the impurity scattering phase shift is intermediate between the Born and unitary limits and leads to an expectation for large thermoelectric effects. Here, we examine the thermoelectric response of a d-wave superconductor connected to normal-metal reservoirs under a temperature bias using a fully self-consistent quasiclassical theory. The thermoelectrically induced quasiparticle current is cancelled by superflow in an open circuit setup, but at the cost of a charge imbalance induced at the contacts and extending across the structure. We investigate the resulting thermopower and thermophase and their dependencies on scattering phase shift, mean free path, and interface transparency. For crystal-axis orientations such that surface-bound zero-energy Andreev states are formed, the thermoelectric effect is reduced as a result of locally reduced electron-hole asymmetry. For a semiballistic superconductor with good contacts, we find thermopowers of order several μV/K, suggesting a thermovoltage measurement as a promising path to investigate thermoelectricity in unconventional superconductors.

Författare

Kevin Marc Seja

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Louhane Jacob

École Normale Supérieure de Lyon

Tomas Löfwander

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Physical Review B

24699950 (ISSN) 24699969 (eISSN)

Vol. 105 10 104506

Ämneskategorier

Fysikalisk kemi

Atom- och molekylfysik och optik

Den kondenserade materiens fysik

DOI

10.1103/PhysRevB.105.104506

Mer information

Senast uppdaterat

2022-04-07