Pumping in a mesoscopic ring with Ahronov-Casher effect

TL;DR

This paper explores how parametric pumping in a mesoscopic ring with Aharonov-Casher and Aharonov-Bohm effects can generate pure spin and charge currents by tuning tunnel barriers and modulating electric or magnetic fields.

Contribution

It demonstrates the conditions for using an AB-AC ring as a pure spin pump, integrating effects of symmetry breaking and parametric modulation.

Findings

Pure spin current can be generated via symmetry interplay.

Tuning tunnel barrier strength controls current generation.

Results applicable to Rashba-gate-controlled rings.

Abstract

We investigate parametric pumping of spin and charge currents in a mesoscopic ring interrupted by a tunnel barrier in presence of Aharonov-Casher (AC) effect and Aharonov-Bohm (AB) flux along the axis of the same ring. Generation of a dc current is achieved by tuning the tunnel barrier strength and modulating in time either a radial(transverse) electric field or the magnetic flux. A pure spin current is generated by the interplay of breaking spin reversal symmetry, due to AC effect, and time-reversal symmetry breaking, intrinsic in parametric pumping procedure. We analyze the conditions for operating the AB-AC ring as a pure spin pump useful in spintronics and discuss generalization of our results to Rashba-gate-controlled rings.