Description
We theoretically consider periodically driven Bose-Einstein condensates whose scattering length is modulated sinusoidally. In experiments, such superfluids have been observed to develop Faraday waves [1] and pattern forming dynamics [2,3]. However, due to the absence of dissipative restoring forces, these systems rapidly transition to quantum turbulence. By introducing a phenomenological viscous damping to the Hamiltonian, we are able to stabilize the exponentially growing sub-harmonic Faraday instability, observing driven-dissipative steady states. For one-dimensional systems we have measured the Faraday instability threshold as a function of the driving frequency, finding agreement with classical fluid dynamics in the high frequency limit. For low driving frequencies, quantum confinement dominates the onset of Faraday waves. For two-dimensional systems the pattern forming dynamics is much richer with observed steady state patterns ranging from square and triangular lattices to quasi-crystalline patterns strongly influenced by the boundary interactions. Interestingly, the viscous term that enables the emergence of these steady-states is closely connected to analogue gravity and Fisher information and these intriquing connections are the subjects of ongoing investigations.
[1] P. Engels, C. Atherton, and M. A. Hoefer, Observation of Faraday Waves in a Bose-Einstein Condensate, Physical Review Letters 98, 095301 (2007).
[2] Z. Zhang, K.-X. Yao, L. Feng, J. Hu & C. Chin,Pattern formation in a driven Bose–Einstein condensate, Nature Physics 16, 652 (2020).
[3] N. Liebster, M. Sparn, E. Kath, J. Duchene, H. Strobel & M.K. Oberthaler, Supersolid-like sound modes in a driven quantum gas, Nature Physics 21, 1064(2025).
| I am the presenting author | Yes |
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