1. Quantum dynamics of a binary mixture of BECs in a double-well potential: a HolsteinPrimakoff approach
- Author
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Adele Naddeo, Roberta Citro, Edmond Orignac, Unitá Operativa di Salerno, CNR-SPIN, Dipartimento di Fisica ' E. R. Caianiello ', Università degli Studi di Salerno (UNISA), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Dipartamento di Fisica 'E. R. Caianiello', and Università degli Studi di Salerno = University of Salerno (UNISA)
- Subjects
Holstein-Primakoff transformation ,Spin states ,[PHYS.COND.GAS]Physics [physics]/Condensed Matter [cond-mat]/Quantum Gases [cond-mat.quant-gas] ,Atomic Physics (physics.atom-ph) ,74.50.+r ,Quantum dynamics ,Semiclassical physics ,FOS: Physical sciences ,Double-well potential ,01 natural sciences ,010305 fluids & plasmas ,Physics - Atomic Physics ,symbols.namesake ,Quantum mechanics ,0103 physical sciences ,67.85.Fg ,010306 general physics ,Quantum tunnelling ,Boson ,Physics ,Condensed Matter::Quantum Gases ,Condensed Matter::Other ,Bose-Einstein condensates ,03.75.Lm ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Quantum evolution ,mixtures ,Quantum Gases (cond-mat.quant-gas) ,symbols ,03.75.Lm 03.75.Mn 75.10.Jm ,Hamiltonian (quantum mechanics) ,Condensed Matter - Quantum Gases - Abstract
We study the quantum dynamics of a binary mixture of Bose-Einstein condensates (BEC) in a double-well potential starting from a two-mode Bose-Hubbard Hamiltonian. Focussing on the regime where the number of atoms is very large, a mapping onto a SU(2) spin problem together with a Holstein-Primakoff transformation is performed. The quantum evolution of the number difference of bosons between the two wells is investigated for different initial conditions, which range from the case of a small imbalance between the two wells to a coherent spin state. The results show an instability towards a phase-separation above a critical positive value of the interspecies interaction while the system evolves towards a coherent tunneling regime for negative interspecies interactions. A comparison with a semiclassical approach is discussed together with some implications on the experimental realization of phase separation with cold atoms., 12 pages, 7 figures, accepted for publication in J. Phys. B
- Published
- 2011
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