Robust adiabatic approach to optical spin entangling in coupled quantum dots

Gauger, Erik M., Nazir, Ahsan, Benjamin, Simon C., Stace, Thomas M. and Lovett, Brendon W. (2008) Robust adiabatic approach to optical spin entangling in coupled quantum dots. New Journal of Physics, 10 Article Number: 073016. doi:10.1088/1367-2630/10/7/073016

Author Gauger, Erik M.
Nazir, Ahsan
Benjamin, Simon C.
Stace, Thomas M.
Lovett, Brendon W.
Title Robust adiabatic approach to optical spin entangling in coupled quantum dots
Journal name New Journal of Physics   Check publisher's open access policy
ISSN 1367-2630
Publication date 2008-07-08
Year available 2008
Sub-type Article (original research)
DOI 10.1088/1367-2630/10/7/073016
Open Access Status DOI
Volume 10
Start page Article Number: 073016
Total pages 25
Editor E. Bodenschatz
Place of publication Bristol, U.K.
Publisher Institute of Physics Publishing
Language eng
Subject C1
970102 Expanding Knowledge in the Physical Sciences
020604 Quantum Optics
Abstract Excitonic transitions offer a possible route to ultrafast optical spin manipulation in coupled nanostructures. We perform here a detailed study of the three principal exciton-mediated decoherence channels for optically controlled electron spin qubits in coupled quantum dots: radiative decay of the excitonic state, exciton–phonon interactions, and Landau–Zener transitions between laser-dressed states. We consider a scheme for producing an entangling controlled-phase gate on a pair of coupled spins which, in its simplest dynamic form, renders the system subject to fast decoherence rates associated with exciton creation during the gating operation. In contrast, we show that an adiabatic approach employing off-resonant laser excitation allows us to suppress all sources of decoherence simultaneously, significantly increasing the fidelity of operations at only a relatively small gating time cost. We find that controlled-phase gates accurate to one part in 102 can realistically be achieved with the adiabatic approach, whereas the conventional dynamic approach does not appear to support a fidelity suitable for scalable quantum computation. Our predictions could be demonstrated experimentally in the near future.
Keyword Excitonic transitions
Charge Qubits
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2009 Higher Education Research Data Collection
School of Mathematics and Physics
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Citation counts: TR Web of Science Citation Count  Cited 18 times in Thomson Reuters Web of Science Article | Citations
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Created: Fri, 20 Mar 2009, 21:57:39 EST by Jo Hughes on behalf of School of Mathematics & Physics