Persistent Current From the Competition Between Zeeman Coupling and Spin-Orbit Interaction

TL;DR

This paper investigates how Zeeman coupling and spin-orbit interaction influence persistent currents in mesoscopic rings, revealing distinct symmetry-breaking effects and periodic current direction changes related to particle number.

Contribution

It introduces a non-adiabatic Aharonov-Anandan phase approach to analyze the interplay of Zeeman coupling and spin-orbit interaction in mesoscopic rings, highlighting their different effects on time-reversal symmetry.

Findings

Zeeman coupling breaks time-reversal symmetry differently than magnetic flux.

Persistent current direction varies periodically with particle number due to Zeeman coupling.

Magnetic flux determines current direction solely by its sign.

Abstract

Applying the non-adiabatic Aharonov-Anandan phase approach to a mesoscopic ring with non-interacting many electrons in the presence of the spin-orbit interaction, Zeeman coupling and magnetic flux, we show that the time-reversal symmetry breaking due to Zeeman coupling is intrinsically different from that due to magnetic flux. We find that the direction of the persistent currents induced by the Zeeman coupling changes periodically with the particle number, while the magnetic flux determines the direction of the induced currents by its sign alone.