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Published on: March 30, 2017
Nonequilibrium Josephson oscillations in Bose-Einstein condensates without dissipation.
Mauricio Trujillo-Martinez1, Anna Posazhennikova, Johann Kroha
1Physikalisches Institut and Bethe Center for Theoretical Physics, Universität Bonn, Nussallee, 12, D-53115 Bonn, Germany.
Physical Review Letters
|October 2, 2009
Summary
Interacting Bose-Einstein condensates exhibit undamped Josephson oscillations in a double-well trap. Beyond a critical time, quasiparticle-assisted tunneling and Rabi oscillations disrupt these oscillations, destroying self-trapped states.
Area of Science:
- Quantum Dynamics
- Atomic, Molecular & Optical Physics
- Condensed Matter Physics
Background:
- Bose-Einstein condensates (BECs) are quantum states of matter with unique properties.
- Josephson oscillations describe particle transfer between two weakly linked quantum systems.
- Understanding BEC dynamics in confined potentials is crucial for quantum technologies.
Purpose of the Study:
- To investigate the quantum dynamics of Josephson oscillations in interacting BECs within a finite double-well trap.
- To identify the conditions and mechanisms governing undamped oscillations and their eventual breakdown.
Main Methods:
- Detailed quantum dynamical simulations were employed.
- The study focused on a finite-size double-well trap confining interacting BECs.
- Analysis included the role of quasiparticle excitations and their impact on Josephson dynamics.
Main Results:
- Multiple undamped Josephson oscillations were observed up to a characteristic time scale (τc) without quasiparticle excitation.
- Beyond τc, dynamics are dominated by fast, quasiparticle-assisted Josephson tunneling.
- Rabi oscillations between discrete quasiparticle levels significantly influence junction dynamics.
Conclusions:
- The observed undamped oscillations may explain recent experimental findings.
- Fast quasiparticle-assisted tunneling and Rabi oscillations are predicted to destroy initially self-trapped BEC states.
- This research provides insights into the complex quantum dynamics of BECs in Josephson junctions.
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