Thermoelectric properties of inversion symmetry broken Weyl semimetal–Weyl superconductor hybrid junctions

Abstract

We theoretically investigate the thermoelectric properties (electronic contribution) of a hybrid structure comprising an inversion symmetry broken Weyl semimetal (WSM) and intrinsic Weyl superconductor (WSC) with $s$-wave pairing, employing the Blonder-Tinkham-Klapwijk formulation for noninteracting electrons. Our study unfolds interesting features for various relevant physical quantities such as thermal conductance, the thermoelectric coefficient, and the corresponding figure of merit. We also explore the effects of an interfacial insulating (I) barrier (WSM-I-WSC setup) on the thermoelectric response in the thin barrier limit. Further, we compute the ratio of the thermal to the electrical conductance in different temperature regimes and find that the Wiedemann-Franz law is violated for small temperatures (below critical temperature ${T}_{c}$) near the Weyl points while it saturates to the Lorentz number, away from the Weyl points, at all temperatures irrespective of the barrier strength. We compare and contrast this behavior with other Dirac material heterostructures and provide a detailed analysis of the thermal transport. Our study can facilitate the fabrication of mesoscopic thermoelectric devices based on WSMs.