Journal article
Robust adiabatic approach to optical spin entangling in coupled quantum dots
- 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.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 1.0MB, Terms of use)
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- Publisher copy:
- 10.1088/1367-2630/10/7/073016
Authors
Contributors
+ Ministry of Education, S
- Role:
- Funder
+ Deutsche Physikalische Gesellschaft
- Role:
- Other
- Publisher:
- Institute of Physics Publishing Ltd
- Journal:
- New Journal of Physics More from this journal
- Volume:
- 10
- Issue:
- 7
- Article number:
- 073016
- Publication date:
- 2008-07-01
- Edition:
- Publisher's version
- DOI:
- EISSN:
-
1367-2630
- Language:
-
English
- Keywords:
- Subjects:
- UUID:
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uuid:e53818e5-71d5-4173-97ad-83b7ebc226e2
- Local pid:
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ora:2487
- Deposit date:
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2009-01-09
Terms of use
- Copyright holder:
- IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
- Copyright date:
- 2008
- Notes:
- Citation: Gauger, E. M., Nazir, A., Benjamin, S. C., Stace, T. M. & Lovett, B. W. (2008). 'Robust adiabatic approach to optical spin entangling in coupled quantum dots', New Journal of Physics, 10(7), 073016. [Available at http://www.njp.org]. This is an Open Access article published under the terms of the Creative Commons Attribution-Non-Commercial-Share Alike 2.5 licence (http://creativecommons.org/licenses/by-nc-sa/2.5/deed.en_GB). This licence permits third-party users to copy, distribute and display the published version of the article, and create derivative works, subject to appropriate acknowledgement of the original authors, and provided the article is not used for commercial purposes. If you alter, transform, or build upon this work, you may distribute the resulting work only under a licence identical to this one. For any reuse or distribution, you must make clear to others the licence terms of this work.
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