Universal Rashba Spin Precession of Two-Dimensional Electrons and Holes

TL;DR

This paper demonstrates that Rashba spin precession in two-dimensional electrons and holes leads to a universal oscillation period in current modulation, supporting the feasibility of spin transistors with holes and simplifying their analysis.

Contribution

It derives a simple analytical expression for current modulation in Rashba systems, showing universality and applicability to both electrons and holes in spin transistor designs.

Findings

Universal oscillation period in current modulation

Feasibility of spin transistors with holes

Analytical formulas match numerical models

Abstract

We study spin precession due to Rashba spin splitting of electrons and holes in semiconductor quantum wells. Based on a simple analytical expression that we derive for the current modulation in a broad class of experimental situations of ferromagnet/nonmagnetic semiconductor/ferromagnet hybrid structures, we conclude that the Datta-Das spin transistor (i) is feasible with holes and (ii) its functionality is not affected by integration over injection angles. The current modulation shows a universal oscillation period, irrespective of the different forms of the Rashba Hamiltonian for electrons and holes. The analytic formulas approximate extremely well exact numerical calculations of a more elaborate Kohn--Luttinger model.