Magnetic field influence on the proximity effect in semiconductor - superconductor hybrid structures and their thermal conductance

TL;DR

This paper investigates how magnetic fields affect the proximity effect and thermal conductance in semiconductor-superconductor hybrid structures, revealing spectral shifts and nonmonotonic thermal behavior in ballistic quasi-one-dimensional channels.

Contribution

It demonstrates the influence of magnetic fields on the proximity effect via diamagnetic screening and predicts nonmonotonic thermal conductance behavior in Q1D systems.

Findings

Magnetic fields shift the proximity-induced minigap in Q1D systems.

Thermal conductance shows nonmonotonic behavior at specific temperatures.

Spectral features are affected by supercurrent flow and magnetic screening.

Abstract

We show that a magnetic field can influnce the proximity effect in NS junctions via diamagnetic screening current flowing in the superconductor. Using ballistic quasi-one-dimensional (Q1D) electron channels as an example, we show that the supercurrent flow shifts the proximity-induced minigap in the excitation spectrum of a Q1D system from the Fermi level to higher quasiparticle energies. Thermal conductance of a Q1D channel (normalized by that of a normal Q1D ballistic system) is predicted to manifest such a spectral feature as a nonmonotonic behavior at temperatures corresponding to the energy of excitation into the gapful part of the spectrum.