Ground-state properties of attractive bosons in mesoscopic 1D ring lattices Export

@article{citeulike:5897521, abstract = {We consider a one-dimensional Bose-Hubbard model describing attractive ultracold bosons trapped in an M-site ring optical lattice within a variational su(M)-coherent-state approach where the attractive-boson dynamics is reformulated in terms of (modified) discrete nonlinear Schrodinger equations. The delocalized, exact ground state of this model can be shown to be well represented as a Schrodinger-cat-like state by coherently superimposing the space-localized ground states obtained by our variational approach. In this paper we focus on two aspects of such space-localized (semiclassical) ground states. First, we prove that the (space-like) su(M) coherent states involved in our variational approach can be recast as momentum-like su(M) coherent states. Based on this property we show that the momentum-space boson distribution of Schrodinger-cat-like states exhibits unexpected features. Secondly, we study the low-energy modes of the discrete nonlinear Schrodinger equations showing that, for sufficiently small lattices, the ground state of the system exhibits a transition controlled by the model parameters from a single-pulse (localized) soliton mode to the superfluid (delocalized) mode. The non-trivial dependence of this effect on the lattice size is also discussed.}, author = {Buonsante, P. and Kevrekidis, P. and Penna, V. and Vezzani, A.}, citeulike-article-id = {5897521}, citeulike-linkout-0 = {http://dx.doi.org/10.1088/0953-4075/39/10/S08}, doi = {10.1088/0953-4075/39/10/S08}, journal = {Journal of Physics B: Atomic, Molecular and Optical Physics}, keywords = {1d, attractive\_interaction, bifurcations, discrete\_self-trapping}, number = {10}, pages = {S77--S87}, posted-at = {2009-10-06 10:05:03}, priority = {0}, title = {Ground-state properties of attractive bosons in mesoscopic 1D ring lattices}, url = {http://dx.doi.org/10.1088/0953-4075/39/10/S08}, volume = {39}, year = {2006} }

TY - JOUR ID - citeulike:5897521 L3 - citeulike-article-id:5897521 N2 - We consider a one-dimensional Bose-Hubbard model describing attractive ultracold bosons trapped in an M-site ring optical lattice within a variational su(M)-coherent-state approach where the attractive-boson dynamics is reformulated in terms of (modified) discrete nonlinear Schrodinger equations. The delocalized, exact ground state of this model can be shown to be well represented as a Schrodinger-cat-like state by coherently superimposing the space-localized ground states obtained by our variational approach. In this paper we focus on two aspects of such space-localized (semiclassical) ground states. First, we prove that the (space-like) su(M) coherent states involved in our variational approach can be recast as momentum-like su(M) coherent states. Based on this property we show that the momentum-space boson distribution of Schrodinger-cat-like states exhibits unexpected features. Secondly, we study the low-energy modes of the discrete nonlinear Schrodinger equations showing that, for sufficiently small lattices, the ground state of the system exhibits a transition controlled by the model parameters from a single-pulse (localized) soliton mode to the superfluid (delocalized) mode. The non-trivial dependence of this effect on the lattice size is also discussed. IS - 10 JF - Journal of Physics B: Atomic, Molecular and Optical Physics EP - S87 TI - Ground-state properties of attractive bosons in mesoscopic 1D ring lattices VL - 39 SP - S77 KW - 1d KW - attractive_interaction KW - bifurcations KW - discrete_self-trapping AU - Buonsante, P AU - Kevrekidis, P AU - Penna, V AU - Vezzani, A PY - 2006/// UR - http://dx.doi.org/10.1088/0953-4075/39/10/S08 ER -