A one-dimensional spin-orbit interferometer

TL;DR

This paper proposes a spin-orbit interferometer using quantum point contacts to observe nonadiabatic electron spin precession, revealing new resonance phenomena and enabling direct measurement of spin-orbit interactions in 1D systems.

Contribution

It introduces a novel device setup for detecting spin-orbit effects via nonadiabatic spin precession and resonance patterns in a ballistic 1D system.

Findings

Resonant peaks are influenced by non-abelian phase from spin precession.

A new resonance type with suppressed transmission is identified.

Resonance shifts depend on spin-orbit interaction strength.

Abstract

We demonstrate that the combination of an external magnetic field and the intrinsic spin-orbit interaction results in nonadiabatic precession of the electron spin after transmission through a quantum point contact (QPC). We suggest that this precession may be observed in a device consisting of two QPCs placed in series. The pattern of resonant peaks in the transmission is strongly influenced by the non-abelian phase resulting from this precession. Moreover, a novel type of resonance which is associated with suppressed, rather than enhanced, transmission emerges in the strongly nonadiabatic regime. The shift in the resonant transmission peaks is dependent on the spin-orbit interaction and therefore offers a novel way to directly measure these interactions in a ballistic 1D system.