Geometric spin manipulation in semiconductor quantum dots

TL;DR

This paper introduces a method for rapid spin flipping in semiconductor quantum dots using adiabatic transport and geometric phases, potentially enabling faster quantum operations before decoherence occurs.

Contribution

It demonstrates a novel geometric phase-based spin flip technique in quantum dots that is faster than decoherence times, requiring both Rashba and Dresselhaus couplings.

Findings

Spin flip time estimated at ~2 picoseconds

Spin flip is feasible with both Rashba and Dresselhaus couplings

Method outperforms decoherence times in quantum dots

Abstract

We propose a method to flip the spin completely by an adiabatic transport of quantum dots. We show that it is possible to flip the spin by inducing a geometric phase on the spin state of a quantum dot. We estimate the geometric spin flip time (approximately 2 pico-sec) which turned out to be much shorter than the experimentally reported decoherence time (approx. 100 nano-sec) that would provide an alternative means of fliping the spin before reaching decoherence. It is important that both the Rashba coupling and the Dresselhaus coupling are present for inducing a phase necessary for spin flip. If one of them is absent, the induced phase is trivial and irrelevant for spin-flip.