From the superfluid to the Mott regime and back: triggering a non-trivial dynamics in an array of coupled condensates

Anno: 2004

Autori: Buonsante P., Franzosi R., Penna V.

Affiliazione autori: Dipartimento di Fisica, Politecnico di Torino, INFM UdR Torino, Cso Duca degli Abruzzi 24, I-10129 Torino, Italy; Dipartimento di Fisica, Università di Pisa, INFM UdR di Pisa, Via Buonarroti 2, I-56127 Pisa, Italy

Abstract: We consider a system formed by an array of Bose-Einstein condensates trapped in a harmonic potential with a superimposed periodic optical potential. Starting from the boson field Hamiltonian, appropriate to describe a dilute gas of bosonic atoms, we reformulate the system dynamics within the Bose-Hubbard model scenario. Then we analyse the effective dynamics of the system when the optical-potential depth is suddenly varied according to a procedure applied in many of the recent experiments on superfluid-Mott transition in Bose-Einstein condensates. Initially the condensate array generated in a weak optical potential is assumed to be in the superfluid ground state which is well described in terms of coherent states. At a given time, the optical-potential depth is suddenly increased and, after a waiting time, it is quickly decreased so that the initial depth is restored. We compute the system-state evolution and show that the potential jump brings on an excitation of the system, incorporated in the final condensate wavefunctions, whose effects are analysed in terms of two-site correlation functions and of on-site population oscillations. Also we show how too long a waiting time can destroy completely the coherence of the final state, making it unobservable.

Giornale/Rivista: JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

Volume: 37 (7)      Da Pagina: S195  A: S203

Parole chiavi: Correlation methods; Hamiltonians; Harmonic analysis; Particle optics; Population statistics; Potentiometers (resistors); Superfluid helium; Systems analysis; Waveform analysis, Bose-Einstein condensates; Bose-Hubbard model; Harmonic potential; Mott transition; Optical potential, Gas condensates
DOI: 10.1088/0953-4075/37/7/065

Citazioni: 7
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2025-05-18
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