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Nuclear spin diffusion in the central spin system of a GaAs/AlGaAs quantum dot.

Published version
Peer-reviewed

Repository DOI


Type

Article

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Authors

Millington-Hotze, Peter  ORCID logo  https://orcid.org/0000-0002-0861-7457
Manna, Santanu 
Covre da Silva, Saimon F  ORCID logo  https://orcid.org/0000-0003-4977-1933
Chekhovich, Evgeny A  ORCID logo  https://orcid.org/0000-0003-1626-9015

Abstract

The spin diffusion concept provides a classical description of a purely quantum-mechanical evolution in inhomogeneously polarized many-body systems such as nuclear spin lattices. The central spin of a localized electron alters nuclear spin diffusion in a way that is still poorly understood. Here, spin diffusion in a single GaAs/AlGaAs quantum dot is witnessed in the most direct manner from oscillatory spin relaxation dynamics. Electron spin is found to accelerate nuclear spin relaxation, from which we conclude that the long-discussed concept of a Knight-field-gradient diffusion barrier does not apply to GaAs epitaxial quantum dots. Our experiments distinguish between non-diffusion relaxation and spin diffusion, allowing us to conclude that diffusion is accelerated by the central electron spin. Such acceleration is observed up to unexpectedly high magnetic fields - we propose electron spin-flip fluctuations as an explanation. Diffusion-limited nuclear spin lifetimes range between 1 and 10 s, which is sufficiently long for quantum information storage and processing.

Description

Keywords

5108 Quantum Physics, 51 Physical Sciences, 5104 Condensed Matter Physics

Journal Title

Nat Commun

Conference Name

Journal ISSN

2041-1723
2041-1723

Volume Title

14

Publisher

Springer Science and Business Media LLC