Persistent spin and charge currents in an Aharonov–Casher conducting ring

Abstract

We investigate the persistent spin and charge currents within an open mesoscopic ring embedded in a textured electric field. The persistent spin and charge currents are obtained analytically, and can be controlled by the electric field. Since the spin-up (down) electron can feel the different transverse spin forces generated by the spin–orbit coupling, the spin-up (down) electron will travel clockwise (anticlockwise) along the ring. As a result, the persistent charge current will change its direction within the ring according to different spin state electron injections, whilst the persistent spin current remains in the same direction. A pure persistent spin current, without any accompanying charge current, can be produced by tuning the strength and/or the angle of the textured electric field.