Robust adiabatic approach to optical spin entangling in coupled quantum dots
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 e...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal article |
| Language: | English |
| Published: |
Institute of Physics Publishing Ltd
2008
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| Subjects: |
| _version_ | 1797100604423667712 |
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| author | Gauger, E Nazir, A Benjamin, S Stace, T Lovett, B |
| author2 | Deutsche Physikalische Gesellschaft |
| author_facet | Deutsche Physikalische Gesellschaft Gauger, E Nazir, A Benjamin, S Stace, T Lovett, B |
| author_sort | Gauger, E |
| collection | OXFORD |
| description | 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. |
| first_indexed | 2024-03-07T05:39:54Z |
| format | Journal article |
| id | oxford-uuid:e53818e5-71d5-4173-97ad-83b7ebc226e2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:39:54Z |
| publishDate | 2008 |
| publisher | Institute of Physics Publishing Ltd |
| record_format | dspace |
| spelling | oxford-uuid:e53818e5-71d5-4173-97ad-83b7ebc226e22022-03-27T10:22:21ZRobust adiabatic approach to optical spin entangling in coupled quantum dotsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e53818e5-71d5-4173-97ad-83b7ebc226e2MaterialsPhysicsAtomic and laser physicsEnglishOxford University Research Archive - ValetInstitute of Physics Publishing Ltd2008Gauger, ENazir, ABenjamin, SStace, TLovett, BDeutsche Physikalische GesellschaftMinistry of Education, SExcitonic 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. |
| spellingShingle | Materials Physics Atomic and laser physics Gauger, E Nazir, A Benjamin, S Stace, T Lovett, B Robust adiabatic approach to optical spin entangling in coupled quantum dots |
| title | Robust adiabatic approach to optical spin entangling in coupled quantum dots |
| title_full | Robust adiabatic approach to optical spin entangling in coupled quantum dots |
| title_fullStr | Robust adiabatic approach to optical spin entangling in coupled quantum dots |
| title_full_unstemmed | Robust adiabatic approach to optical spin entangling in coupled quantum dots |
| title_short | Robust adiabatic approach to optical spin entangling in coupled quantum dots |
| title_sort | robust adiabatic approach to optical spin entangling in coupled quantum dots |
| topic | Materials Physics Atomic and laser physics |
| work_keys_str_mv | AT gaugere robustadiabaticapproachtoopticalspinentanglingincoupledquantumdots AT nazira robustadiabaticapproachtoopticalspinentanglingincoupledquantumdots AT benjamins robustadiabaticapproachtoopticalspinentanglingincoupledquantumdots AT stacet robustadiabaticapproachtoopticalspinentanglingincoupledquantumdots AT lovettb robustadiabaticapproachtoopticalspinentanglingincoupledquantumdots |