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Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
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Berezinskii-Kosterlitz-Thouless phase induced by dissipating quasisolitons
Krzysztof Gawryluk1, Mirosław Brewczyk2
1Wydział Fizyki, Uniwersytet w Białymstoku, ul. K. Ciołkowskiego 1L, 15245, Białystok, Poland. k.gawryluk@uwb.edu.pl.
Scientific Reports
|May 25, 2021
Summary
Sound propagation in Bose gases reveals complex behaviors. Strong disturbances create quasisolitons that evolve into a Berezinskii-Kosterlitz-Thouless (BKT) phase, exhibiting quasi-long-range order.
Area of Science:
- Quantum physics
- Condensed matter physics
- Ultracold atomic gases
Background:
- Bose gases exhibit unique quantum phenomena.
- Understanding sound propagation is key to characterizing Bose gas dynamics.
Purpose of the Study:
- To theoretically investigate sound propagation in 2D Bose gases.
- To analyze density wave properties under weak and strong perturbations.
Main Methods:
- Classical fields approximation.
- Theoretical analysis of density wave generation and evolution.
Main Results:
- Weak perturbations yield hydrodynamic or collisionless sound.
- Strong perturbations generate quasisolitons with complex internal structures.
- Quasisolitons fragment into vortex pairs, leading to an equilibrium state.
- This equilibrium state exhibits quasi-long-range order, identified as the Berezinskii-Kosterlitz-Thouless (BKT) phase.
Conclusions:
- Strong perturbations in Bose gases lead to novel phenomena beyond simple sound waves.
- The emergence of the BKT phase from quasisoliton decay highlights complex dynamics in 2D Bose systems.
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