Superconducting diode effect due to magnetochiral anisotropy in topological insulator and Rashba nanowires

TL;DR

This paper investigates the superconducting diode effect in topological insulator and Rashba nanowires, showing how magnetic fields and chemical potential influence the effect and can signal topological phase transitions.

Contribution

It demonstrates how the superconducting diode effect can serve as a probe for inversion symmetry breaking and topological phase transitions in 1D nanowire systems.

Findings

Superconducting diode effect depends on magnetic field orientation.

The effect varies with chemical potential and indicates topological phase transition.

Magnetic field components influence the magnitude of the diode effect.

Abstract

The critical current of a superconductor can depend on the direction of current flow due to magnetochiral anisotropy when both inversion and time-reversal symmetry are broken, an effect known as the superconducting (SC) diode effect. Here, we consider one-dimensional (1D) systems in which superconductivity is induced via the proximity effect. In both topological insulator and Rashba nanowires, the SC diode effect due to a magnetic field applied along the spin-polarization axis and perpendicular to the nanowire provides a measure of inversion symmetry breaking in the presence of a superconductor. Furthermore, a strong dependence of the SC diode effect on an additional component of magnetic field applied parallel to the nanowire as well as on the position of the chemical potential can be used to detect that a device is in the region of parameter space where the phase transition to topological superconductivity is expected to arise.