Orbital magnetic phase and pure persistent spin current in spin-orbit coupling mesoscopic rings

TL;DR

This paper analytically investigates the ground-state properties of mesoscopic rings with spin-orbit coupling, revealing a novel orbital magnetic phase characterized by pure persistent spin current and self-sustained magnetic flux.

Contribution

It introduces the concept of orbital magnetic phase in mesoscopic rings with spin-orbit coupling, highlighting the coexistence of pure spin current and self-sustained flux, and explores phase transitions induced by system parameters.

Findings

Coexistence of pure PSC and SSMF in one-dimensional rings.

Phase transition between OMP and non-OMP by tuning spin-orbit coupling or electron number.

Analytical expressions for ground-state properties including spin polarization and persistent currents.

Abstract

By solving the Rashba model of mesoscopic rings, we give analytically the ground-state properties of the ring, including the spin polarization, the persistent charge and spin currents (PCC and PSC). These ground-state properties can be given based on four kinds of electron numbers in rings. The effect of the self-inductance of the ring leads to the self-sustained magnetic flux (SSMF) and the self-sustained PCC and PSC, which break spontaneously time-reversal symmetry to form orbital magnetic phase (OMP). To tune the spin-orbit coupling strength or electron number of the ring can induce the phase transition between the OMP and non-OMP. For exact one-dimensional rings we find the coexistence of the pure PSC and SSMF. This property of the pure PSC may provide a new scheme to measure the pure PSC.