Chekhovich, E.A. (2017) Decoherence and fluctuation dynamics of the quantum dot nuclear spin bath probed by nuclear magnetic resonance. In: Journal of Physics: Conference Series. 33rd International Conference on the Physics of Semiconductors, 31 July 31 - 5 August 2016, Beijing, China. IOP Publishing
Abstract
Dynamics of nuclear spin decoherence and nuclear spin flip-flops in self-assembled InGaAs/GaAs quantum dots are studied experimentally using optically detected nuclear magnetic resonance (NMR). Nuclear spin-echo decay times are found to be in the range 1-4 ms. This is a factor of ~3 longer than in strain-free GaAs/AlGaAs structures and is shown to result from strain-induced quadrupolar effects that suppress nuclear spin flip-flops. The correlation times of the flip-flops are examined using a novel frequency-comb NMR technique and are found to exceed 1 s, a factor of ~1000 longer than in strain-free structures. These findings complement recent studies of electron spin coherence and reveal the paradoxical dual role of the quadrupolar effects in self-assembled quantum dots: large increase of the nuclear spin bath coherence and at the same time significant reduction of the electron spin-qubit coherence. Approaches to increasing electron spin coherence are discussed. In particular the nanohole filled GaAs/AlGaAs quantum dots are an attractive option: while their optical quality matches the self-assembled dots the quadrupolar effects measured in NMR spectra are a factor of 1000 smaller.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 IOP Publishing Ltd. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number THE ROYAL SOCIETY UF140058 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) EP/N031776/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 14 Sep 2017 11:37 |
Last Modified: | 14 Sep 2017 11:49 |
Published Version: | https://doi.org/10.1088/1742-6596/864/1/012080 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/1742-6596/864/1/012080 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:120992 |
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