Spin states and persistent currents in a mesoscopic ring with an embedded magnetic impurity

TL;DR

This paper theoretically explores how a magnetic impurity and spin-orbit interactions influence spin states and persistent currents in a mesoscopic ring, revealing complex spectral and current behaviors.

Contribution

It introduces a detailed theoretical model analyzing the combined effects of magnetic impurities and spin-orbit interactions on mesoscopic ring properties.

Findings

Magnetic impurity causes energy spectrum gaps and suppresses persistent current oscillations.

Competition between Zeeman and exchange interactions induces ground state transitions.

Spin-orbit interactions significantly alter energy spectrum and charge distribution.

Abstract

Spin states and persistent currents are investigated theoretically in a mesoscopic ring with an embedded magnetic ion under a uniform magnetic field including the spin-orbit interactions. The magnetic impurity acts as a spin-dependent $\delta$-potential for electrons and results in gaps in the energy spectrum, consequently suppresses the oscillation of the persistent currents. The competition between the Zeeman splittings and the $s$-$d$ exchange interaction leads to a transition of the electron ground state in the ring. The interplay between the periodic potential induced by the Rashba and Dresselhaus spin-orbit interactions and the $\delta$-potential induced by the magnetic impurity leads to significant variation in the energy spectrum, charge density distribution, and persistent currents of electrons in the ring.