Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitations
The time-dependent non-equilibrium dynamics of a Bose–Einstein condensate (BEC) typically generates incoherent excitations out of the condensate due to the finite frequencies present in the time evolution. We present a detailed derivation of a general non-equilibrium Greenʼs function technique that...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2015-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/17/1/013006 |
| _version_ | 1797751260737175552 |
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| author | Mauricio Trujillo-Martinez Anna Posazhennikova Johann Kroha |
| author_facet | Mauricio Trujillo-Martinez Anna Posazhennikova Johann Kroha |
| author_sort | Mauricio Trujillo-Martinez |
| collection | DOAJ |
| description | The time-dependent non-equilibrium dynamics of a Bose–Einstein condensate (BEC) typically generates incoherent excitations out of the condensate due to the finite frequencies present in the time evolution. We present a detailed derivation of a general non-equilibrium Greenʼs function technique that describes the coupled time evolution of an interacting BEC and its single-particle excitations in a trap, based on an expansion in terms of the exact eigenstates of the trap potential. We analyze the dynamics of a Bose system in a small double-well potential with initially all particles in the condensate. When the trap frequency is larger than the Josephson frequency, $\Delta \gt {{\omega }_{{\rm J}}}$ , the dynamics changes at a characteristic time, ${{\tau }_{{\rm c}}}$ , abruptly from the slow Josephson oscillations of the BEC to fast Rabi oscillations driven by quasiparticle excitations in the trap. For times $t\lt {{\tau }_{{\rm c}}}$ , the Josephson oscillations are undamped, in agreement with the experiments. We analyze the physical origin of the finite scale ${{\tau }_{{\rm c}}}$ as well as its dependence on the trap parameter Δ . |
| first_indexed | 2024-03-12T16:45:54Z |
| format | Article |
| id | doaj.art-c866991f62c3480086e6bfb44a57d8ad |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:45:54Z |
| publishDate | 2015-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-c866991f62c3480086e6bfb44a57d8ad2023-08-08T14:16:14ZengIOP PublishingNew Journal of Physics1367-26302015-01-0117101300610.1088/1367-2630/17/1/013006Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitationsMauricio Trujillo-Martinez0Anna Posazhennikova1Johann Kroha2Physikalisches Institut and Bethe Center for Theoretical Physics , Universität Bonn, Nussallee, 12, D-53115 Bonn, GermanyDepartment of Physics, Royal Holloway , University of London, Egham, Surrey TW20 0EX, UKPhysikalisches Institut and Bethe Center for Theoretical Physics , Universität Bonn, Nussallee, 12, D-53115 Bonn, GermanyThe time-dependent non-equilibrium dynamics of a Bose–Einstein condensate (BEC) typically generates incoherent excitations out of the condensate due to the finite frequencies present in the time evolution. We present a detailed derivation of a general non-equilibrium Greenʼs function technique that describes the coupled time evolution of an interacting BEC and its single-particle excitations in a trap, based on an expansion in terms of the exact eigenstates of the trap potential. We analyze the dynamics of a Bose system in a small double-well potential with initially all particles in the condensate. When the trap frequency is larger than the Josephson frequency, $\Delta \gt {{\omega }_{{\rm J}}}$ , the dynamics changes at a characteristic time, ${{\tau }_{{\rm c}}}$ , abruptly from the slow Josephson oscillations of the BEC to fast Rabi oscillations driven by quasiparticle excitations in the trap. For times $t\lt {{\tau }_{{\rm c}}}$ , the Josephson oscillations are undamped, in agreement with the experiments. We analyze the physical origin of the finite scale ${{\tau }_{{\rm c}}}$ as well as its dependence on the trap parameter Δ .https://doi.org/10.1088/1367-2630/17/1/013006Bose–Josephson junctionnon equilibrium dynamicsincoherent excitations67.85.-d67.85.De03.75.Lm |
| spellingShingle | Mauricio Trujillo-Martinez Anna Posazhennikova Johann Kroha Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitations New Journal of Physics Bose–Josephson junction non equilibrium dynamics incoherent excitations 67.85.-d 67.85.De 03.75.Lm |
| title | Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitations |
| title_full | Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitations |
| title_fullStr | Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitations |
| title_full_unstemmed | Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitations |
| title_short | Temporal non-equilibrium dynamics of a Bose–Josephson junction in presence of incoherent excitations |
| title_sort | temporal non equilibrium dynamics of a bose josephson junction in presence of incoherent excitations |
| topic | Bose–Josephson junction non equilibrium dynamics incoherent excitations 67.85.-d 67.85.De 03.75.Lm |
| url | https://doi.org/10.1088/1367-2630/17/1/013006 |
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