Thermal transport in topological-insulator-based superconducting hybrid structures with mixed singlet and triplet pairing states

Abstract

In the framework of the Bogoliubov-de Gennes equation, we investigate the thermal transport properties in topological-insulator-based superconducting hybrid structures with mixed spin-singlet and spin-triplet pairing states, and emphasize the different manifestations of the spin-singlet and spin-triplet pairing states in the thermal transport signatures. It is revealed that the temperature-dependent differential thermal conductance strongly depends on the components of the pairing state, and the negative differential thermal conductance only occurs in the spin-singlet pairing state dominated regime. It is also found that the thermal conductance is profoundly sensitive to the components of the pairing state. In the spin-singlet pairing state controlled regime, the thermal conductance obviously oscillates with the phase difference and junction length. With increasing the proportion of the spin-triplet pairing state, the oscillating characteristic of the thermal conductance fades out distinctly. These results suggest an alternative route for distinguishing the components of pairing states in topological-insulator-based superconducting hybrid structures.

Quasiparticle cooling using a topological insulator–superconductor hybrid junction

“…The role of an insulating interface is reported in Ref. [20] for a topological system. To further investigate on these results, in Fig.…”

“…In Ref. [20] a finite BTK Z parameter induces a cooling power behaving very similarly to the standard BTK case (of Ref. [11]) with respect to Z.…”

“…Hence, we expect a sizable cooling effect when the chemical potential of the surface state is finely tuned very close to the charge neutrality point. We expect to recover cooling power in the retro-reflection regime considering the presence of an insulating interface between the normal region and the superconducting one [20].…”

Superconducting proximity effect in $d$-wave cuprate/ graphene heterostructures

“…This approach has used in Refs. [113,88,89], and the approach can be recast into a boundary problem for scattering matrices [114]. Following this approach, a periodic oscillation of differential conductance as a function of the injection energy was found.…”

Thermoelectric Efficiency of a Topological Nano-Junction

“…While the electrical properties of topological materials have been intensively studied [ 6 , 7 , 8 , 9 , 11 , 12 , 14 , 15 ], thermoelectric performance of these topological based devices has not yet received the same level of attention from the condensed matter community, besides some interesting examples [ 15 , 16 , 17 , 18 ]. The heat production due to Joule heating in nano and micro-devices is one of the biggest problems in current microelectronics, and there is a growing interest on new materials capable of mitigating energy dissipation.…”