Coherent transfer of electron spin correlations assisted by dephasing noise

TL;DR

This paper demonstrates a method where environmental dephasing noise helps transfer and generate entanglement between distant electron spins in quantum dots, leveraging noise to enhance quantum coherence.

Contribution

It introduces a novel entanglement transfer scheme that uses dephasing noise to assist quantum state manipulation without losing coherence.

Findings

Dephasing noise accelerates entanglement transfer via a quantum Zeno effect.

The scheme maintains coherence during the transfer process.

Noise-assisted entanglement generation is feasible in solid-state spin systems.

Abstract

Quantum coherence of superposed states, especially of entangled states, is indispensable for many quantum technologies. However, it is vulnerable to environmental noises, posing a fundamental challenge in solid-state systems including spin qubits. Here we show a scheme of entanglement engineering where pure dephasing assists the generation of quantum entanglement at distant sites in a chain of electron spins confined in semiconductor quantum dots. One party of an entangled spin pair, prepared at a single site, is transferred to the next site and then adiabatically swapped with a third spin using a transition across a multi-level avoided crossing. This process is accelerated by the noise-induced dephasing through a variant of the quantum Zeno effect, without sacrificing the coherence of the entangled state. Our finding brings insight into the spin dynamics in open quantum systems coupled to noisy environments, opening an avenue to quantum state manipulation utilizing decoherence effects.