Influence of the Rashba effect on the Josephson current through a superconductor/Luttinger liquid/superconductor tunnel junction

TL;DR

This paper investigates how Rashba spin-orbit coupling and electron interactions influence the Josephson current in a superconductor/Luttinger liquid/superconductor junction, revealing an anomalous supercurrent and complex plasmonic mode behavior.

Contribution

It demonstrates that Rashba and Zeeman interactions induce a supercurrent without phase difference and shows the impact of dispersion asymmetry on plasmonic modes in the junction.

Findings

Supercurrent persists without phase difference due to Rashba and Zeeman effects.

Dispersion asymmetry causes plasmonic mode spectrum to become quasi-random.

Electron interactions affect the supercurrent and mode behavior.

Abstract

The Josephson current through a 1D quantum wire with Rashba spin-orbit and electron-electron interactions is calculated. We show that the interplay of Rashba and Zeeman interactions gives rise to a supercurrent through the 1D conductor that is anomalous in the sense that it persists in the absence of any phase difference between the two superconducting leads to which it is attached. The electron dispersion asymmetry induced by the Rashba interaction in a Luttinger-liquid wire plays a significant role for poorly transmitting junctions. It is shown that for a weak or moderate electron-electron interaction the spectrum of plasmonic modes confined to the normal part of the junction becomes quasi-random in the presence of dispersion asymmetry.