Electronic spin precession and interferometry from spin-orbital entanglement in a double quantum dot

TL;DR

This paper demonstrates how entangling electron spin with orbital degrees of freedom in a double quantum dot enables geometrical control of spin precession, with potential applications in quantum interferometry and spintronics.

Contribution

It introduces a method to transfer Aharonov-Bohm orbital phase to spin states, enabling coherent spin control via spin-orbital entanglement in a double quantum dot system.

Findings

Coherent spin precession observed in a mixed orbital/spin Kondo regime.

Spin precession can be detected using spin-polarized leads or a metallic loop.

Orbital phase transfer allows geometrical control of spin dynamics.

Abstract

A double quantum dot inserted in parallel between two metallic leads allows to entangle the electron spin with the orbital (dot index) degree of freedom. An Aharonov-Bohm orbital phase can then be transferred to the spinor wavefunction, providing a geometrical control of the spin precession around a fixed magnetic field. A fully coherent behaviour is obtained in a mixed orbital/spin Kondo regime. Evidence for the spin precession can be obtained, either using spin-polarized metallic leads or by placing the double dot in one branch of a metallic loop.