The supercurrent diode effect and nonreciprocal paraconductivity due to the chiral structure of nanotubes

TL;DR

This paper reveals a new mechanism for the supercurrent diode effect and nonreciprocal paraconductivity in chiral nanotubes, independent of spin-orbit coupling, expanding understanding of nonreciprocal superconducting phenomena.

Contribution

It introduces a novel mechanism for supercurrent diode effect in chiral nanotubes that traps magnetic fluxes without relying on spin-orbit coupling or Zeeman fields.

Findings

Supercurrent diode effect observed in chiral nanotubes.

Nonreciprocal paraconductivity near transition temperature.

Parameter dependence characterizes both effects.

Abstract

The research interest in the supercurrent diode effect (SDE) has been growing. It has been found in various kinds of systems, in a large part of which it may be understood by combining spin-orbit coupling and Zeeman field. Here, we show that there exists another mechanism of generating SDE in chiral nanotubes that trap magnetic fluxes, without spin-orbit coupling or Zeeman field. We further show that the same generalized Ginzburg-Landau theory leads to nonreciprocal paraconductivity (NPC) near the transition temperature. The main features of both the SDE and the NPC are revealed by their parameter dependence. Our study suggests a new kind of platforms to explore nonreciprocal properties of superconducting materials. It also provides a theoretical link between the SDE and the NPC, which were often studied separately.