2014/08/14 by Lei Chen, Wu Li, Zhu Chen +2 · 3 citations
Physics and Astronomy · #Bose gas #Cold Atom Physics and Bose-Einstein Condensates #Excitation #Lattice (music) #Optical lattice #Quantum, superfluid, helium dynamics #Spectroscopy #Speed of sound #Strong Light-Matter Interactions #Superfluidity #cond-mat.quant-gas #physics.atom-ph
paper · pdf · doi:10.1007/s10909-014-1210-9
published in Journal of Low Temperature Physics 177(5-6), 291-304 (Springer Science+Business Media) · 10 pages, 5 figures
openalex publication_date 2014/08/14 · arxiv created 2014/12/01 · arxiv updated 2014/12/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A Bose-Einstein condensate (BEC) with periodically modulated interactions (PMI) has emerged as a novel kind of periodic superfluid, which has been recently experimentally created using optical Feshbach resonance. In this paper, we are motivated to investigate the superfluidity of a BEC with PMI trapped in an optical lattice (OL). In particular, we explore the effects of PMI on the sound speed and the dynamical structure factor of the model system. Our numerical results, combined with the analytical results in both the weak-potential limit and the tight-binding limit, have shown that the PMI can strongly modify the sound speed of a BEC. Moreover, we have shown that the effects of PMI on sound speed can be experimentally probed via the dynamic structure factor, where the excitation strength toward the first Bogoliubov band exhibits marked difference from the non- PMI one. Our predictions of the effects of PMI on the sound speed can be tested using the Bragg spectroscopy.