Anisotropic spin transport in two-terminal mesoscopic rings: Rashba and Dresselhaus spin-orbit interactions

Miao Wang,Kai Chang

doi:10.1103/physrevb.77.125330

Abstract

We theoretically investigate the spin transport in two-terminal mesoscopic rings in the presence of both the Rashba spin-orbit interaction (RSOI) and the Dresselhaus spin-orbit interaction (DSOI). We find that the interplay between the RSOI and DSOI breaks the original cylindric symmetry of the mesoscopic rings and consequently leads to the anisotropic spin transport, i.e., the conductance is sensitive to the positions of the incoming and outgoing leads. The anisotropic spin transport can survive even in the presence of disorder caused by impurity elastic scattering in a realistic system.

Highlights

In recent years, the spin-orbit interaction (SOI) in low-dimensional semiconductor structures has attracted considerable attention because of its potential application in all-electrical controlled spintronic devices. [1, 2] There are two types of SOI in conventional semiconductors
We find that the interplay between the Rashba spin-orbit interaction (RSOI) and Dresselhaus spin-orbit interaction (DSOI) leads to a significant change in the transmission, the localization of electrons, and the spin polarization of the current
We study the transport through a mesoscopic ring in the presence of both the RSOI and DSOI

Summary

INTRODUCTION

The spin-orbit interaction (SOI) in low-dimensional semiconductor structures has attracted considerable attention because of its potential application in all-electrical controlled spintronic devices. [1, 2] There are two types of SOI in conventional semiconductors. [15, 16, 17, 18, 19, 20] SOIs in semiconductors behave like an in-plane momentumdependent magnetic field and lead to a lifting of spin degeneracy of energy bands This effective magnetic field induces a wave phase difference between the upper arm and lower arm, resulting in the oscillation of the conductance. [22] The interplay between the RSOI and DSOI results in a periodic potential in an isolated ring, producing the gap in the energy spectrum, suppressing the persistent currents, [22] and breaking the cylindrical symmetry of mesoscopic rings This interesting feature leads to the anisotropic spin transport and could be detected using the transport property in an open two-terminal mesoscopic ring.

THEORETICAL MODEL

RESULTS AND DISCUSSIONS

The spin polarization of current

CONCLUSION