Electron spin rotations induced by oscillating Rashba interaction in a quantum wire

TL;DR

This paper introduces a new method to rotate electron spins in a quantum wire using oscillating Rashba spin-orbit coupling induced by electric gates, eliminating the need for external magnetic fields.

Contribution

The authors propose a novel all-electric technique for spin manipulation in quantum wires via spatial and time modulation of confining potentials, supported by realistic simulations.

Findings

Achieved controlled spin rotations without external magnetic fields.

Demonstrated feasibility with realistic 3D time-dependent simulations.

Potential for scalable quantum spin control in nanodevices.

Abstract

A novel method and nanodevice are introduced that allows to rotate the single electron spin confined in a gated electrostatic InSb nanowire quantum dot. Proposed method does not require application of any (oscillating or static) external magnetic fields. Our proposal instead employs spatial and time modulation of confining potential induced by electric gates, which, in turn leads to oscillating Rashba type spin-orbit coupling. Moving electron back and forth in such a variable Rashba field allows for realization of spin rotations around two different axes separately without using an external magnetic field. The results are supported by realistic three-dimensional time dependent Poisson-Schr\"{o}dinger calculations for systems and material parameters corresponding to experimentally accessible structures.