Tilt-induced anomalous thermal transport in normal/superconducting borophane junctions (1901.11114v2)

Abstract: We study charge and heat transport in normal-metal/superconductor (NS) hybrid junction, based on a tilted anisotropic Dirac material. Using the extended Blonder-Tinkham-Klapwijk formalism, the conductance spectra of NS borophane, a two-dimensional Dirac semimetal with two tilted anisotropic Dirac cones in its dispersion, is investigated. Completely different from the usual normal-metal-superconductor junctions, in spite of the large mismatch in Fermi wavevectores of the normal-metal and superconductor sides of the borophane NS junction, the electron-hole conversion happens with unit probability at normal incidences. Furthermore, we demonstrate that in the heavily doped superconducting regime for heavily doped normal borophane, the electron-hole conversion happens with unit probability, approximately at any incident angle. The dependence of the Andreev with Fermi energy and bias voltage, enable us, selecting the retroconfiguration or specular configuration in types of Andreev reflection processes. We numerically establish an anomalous behavior of thermal conductance in borophane. The tilting of the Dirac cones gives rise to an anomalous behaviour in the thermal conductance of the NS hybrid junction of borophane, such that the thermal conductance decreases by increasing the temperature. Our findings will have potential applications for transport and energy control in superconducting quantum interference devices and hybridized mesoscopic systems.