# Collective modes and superfluidity of a two-dimensional ultracold Bose gas

@article{Singh2020CollectiveMA, title={Collective modes and superfluidity of a two-dimensional ultracold Bose gas}, author={Vijay Pal Singh and Ludwig Mathey}, journal={arXiv: Quantum Gases}, year={2020} }

The collective modes of a quantum liquid shape and impact its properties profoundly, including its emergent phenomena such as superfluidity. Here we present how a two-dimensional Bose gas responds to a moving lattice potential. In particular we discuss how the induced heating rate depends on the interaction strength and the temperature. This study is motivated by the recent measurements of Sobirey {\it et al.} arXiv:2005.07607 (2020), for which we provide a quantitative understanding. Going…

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## References

SHOWING 1-10 OF 42 REFERENCES

Superfluidity and relaxation dynamics of a laser-stirred two-dimensional Bose gas

- Physics
- 2017

We investigate the superfluid behavior of a two-dimensional (2D) Bose gas of $^{87}$Rb atoms using classical field dynamics. In the experiment by R. Desbuquois \textit{et al.}, Nat. Phys. \textbf{8},…

Probing superfluidity of Bose-Einstein condensates via laser stirring

- Physics
- 2016

We investigate the superfluid behavior of a Bose-Einstein condensate of $^{6}\mathrm{Li}$ molecules. In the experiment by Weimer et al. [Phys. Rev. Lett. 114, 095301 (2015)] a condensate is stirred…

Signatures of a universal jump in the superfluid density of a two-dimensional Bose gas with a finite number of particles

- PhysicsPhysical Review A
- 2019

We study, within the classical fields approximation, a two-dimensional weakly interacting uniform Bose gas of a finite number of atoms. By using a grand canonical ensemble formalism we show that such…

Second sound in the BEC-BCS crossover.

- Physics
- 2020

Second sound is an entropy wave which propagates in the superfluid component of a quantum liquid. Because it is an entropy wave, it probes the thermodynamic properties of the quantum liquid which are…

Fermi-to-Bose crossover in a trapped quasi-2D gas of fermionic atoms.

- Physics, MedicineJournal of physics. Condensed matter : an Institute of Physics journal
- 2017

This work presents simple theoretical models describing the gas at different points of the crossover and compares the data to more advanced models, as well as critical phenomena in the Fermi-to-Bose crossover.

Observation of the Berezinskii-Kosterlitz-Thouless Phase Transition in an Ultracold Fermi Gas.

- Physics, MedicinePhysical review letters
- 2015

It is shown that the spatial coherence of the entire trapped system can be characterized by a single temperature-dependent exponent, which suggests that the phase transitions in both the bosonic regime and the strongly interacting crossover regime are of Berezinskii-Kosterlitz-Thouless type and lie within the same universality class.

Sound Propagation in a Uniform Superfluid Two-Dimensional Bose Gas.

- Physics, MedicinePhysical review letters
- 2018

This work excites running and standing waves in a uniform two-dimensional Bose gas and characterize the propagation of sound in both the superfluid and normal regimes.

Two-dimensional weakly interacting Bose gas in the fluctuation region

- Physics
- 2002

We study the crossover between the mean-field and critical behavior of the two-dimensional Bose gas throughout the fluctuation region of the Berezinskii-Kosterlitz-Thouless phase transition point. We…

Berezinskii–Kosterlitz–Thouless crossover in a trapped atomic gas

- Physics, MedicineNature
- 2006

The observation of a BKT-type crossover in a trapped quantum degenerate gas of rubidium atoms is reported, providing direct experimental evidence for the microscopic mechanism underlying the BKT theory, and raising new questions regarding coherence and superfluidity in mesoscopic systems.

Observation of Pair Condensation in the Quasi-2D BEC-BCS Crossover.

- Physics, MedicinePhysical review letters
- 2015

This experiment uses ultracold atoms as a generic model system to study the phase transition from a normal to a condensed phase in a strongly interacting quasi-two-dimensional Fermi gas and obtains the in situ pair momentum distribution of the strongly interacting system.