Dynamical spin-electric coupling in a quantum dot

TL;DR

This paper explores how spin-orbit coupling in quantum dots induces a time-dependent charge density that generates electric fields, enabling non-invasive spin detection and revealing a significant spin relaxation mechanism.

Contribution

It introduces the concept of dynamical spin-electric coupling in quantum dots and analyzes its implications for spin detection and relaxation mechanisms.

Findings

Spin precession produces measurable electric fields outside the quantum dot.

Spin relaxation due to long-range coupling can be comparable or dominant.

Potential applications in spintronics for non-invasive spin detection.

Abstract

Due to the spin-orbital coupling in a semiconductor quantum dot, a freely precessing electron spin produces a time-dependent charge density. This creates a sizeable electric field outside the dot, leading to promising applications in spintronics. The spin-electric coupling can be employed for non-invasive single spin detection by electrical methods. We also consider a spin relaxation mechanism due to long-range coupling to electrons in gates and elsewhere in the system, and find a contribution comparable to, and in some cases dominant over previously discussed mechanisms.