Beyond-Mean-Field Effects in Rabi-Coupled Two-Component Bose-Einstein Condensate

Year: 2021

Authors: Lavoine L.; Hammond A.; Recati A.; Petrov D.S.; Bourdel T.

Autors Affiliation: Univ Paris Saclay, CNRS, UMR 8501, Inst Opt,Lab Charles Fabry, Ave Augustin Fresnel, F-91127 Palaiseau, France; Univ Trento, INO CNR BEC Ctr, I-38123 Povo, Italy; Univ Trento, Dipartimento Fis, I-38123 Povo, Italy; INFN, Trento Inst Fundamental Phys & Applicat, I-38123 Trento, Italy; Univ Paris Saclay, CNRS, LPTMS, F-91405 Orsay, France.

Abstract: We theoretically calculate and experimentally measure the beyond-mean-field (BMF) equation of state in a coherently coupled two-component Bose-Einstein condensate (BEC) in the regime where averaging of the interspecies and intraspecies coupling constants over the hyperfine composition of the single-particle dressed state predicts the exact cancellation of the two-body interaction. We show that with increasing the Rabi-coupling frequency ?, the BMF energy density crosses over from the nonanalytic Lee-Huang-Yang scaling ?n5/2 to an expansion in integer powers of density, where, in addition to a two-body BMF term ?n2?, there emerges a repulsive three-body contribution ?n3/?. We experimentally evidence these two contributions, thanks to their different scaling with ?, in the expansion of a Rabi-coupled two-component K39 condensate in a waveguide. By studying the expansion with and without Rabi coupling, we reveal an important feature relevant for observing BMF effects and associated phenomena in mixtures with spin-asymmetric losses: Rabi coupling helps preserve the spin composition and thus prevents the system from drifting away from the point of the vanishing mean field.

Journal/Review: PHYSICAL REVIEW LETTERS

Volume: 127 (20)      Pages from: 203402-1  to: 203402-6

KeyWords: DROPLETS
DOI: 10.1103/PhysRevLett.127.203402

ImpactFactor: 9.185
Citations: 14
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-06
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