Coherent transfer of electron spin correlations assisted by dephasing noise

Nakajima, T. and Delbecq, M.R. and Otsuka, T. and Amaha, S. and Yoneda, J. and Noiri, A. and Takeda, K. and Allison, G. and Ludwig, Ar. and Wieck, A.D. and Hu, X. and Nori, F. and Tarucha, S.

Volume: 9 Pages:
DOI: 10.1038/s41467-018-04544-7
Published: 2018

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. © 2018 The Author(s).

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