Dynamical classical superfluid-insulator transition in a Bose-Einstein condensate on an optical lattice

We predict a dynamical: classical superfluid-insulator transition in a Bose-Einstein condensate (BEC) trapped in combined optical and axially symmetrical harmonic potentials initiated by the periodic modulation of the radial trapping potential. The transition is marked by a loss of phase coherence in the BEC and a subsequent destruction of the interference pattern upon free:expansion. For a weak modulation of the radial potential the phase coherence is maintained. For a stronger modulation and a longer holding time in the modulated trap, the phase coherence is destroyed thus signalling a classical superfluid-insulator transition. The results are illustrated by a complete numerical solution of the axially symmetrical mean-field Gross-Pitaevskii equation for a repulsive BEC. Suggestions for future experimentation are-made.

Spatially-antisymmetric localization of matter wave in a bichromatic optical lattice

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Two-dimensional dipolar Bose-Einstein condensate bright and vortex solitons on a one-dimensional optical lattice

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Gap solitons in a dipolar Bose-Einstein condensate on a three-dimensional optical lattice

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Localization of a dipolar Bose-Einstein condensate in a bichromatic optical lattice

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Dipolar Bose-Einstein condensate soliton on a two-dimensional optical lattice

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Langevin simulation of scalar fields: Additive and multiplicative noises and lattice renormalization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Higher order Painleve equations and their symmetries via reductions of a class of integrable models

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Soliton dynamics at an interface between a uniform medium and a nonlinear optical lattice

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Symmetry breaking in a localized interacting binary Bose-Einstein condensate in a bichromatic optical lattice

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Cubic interactions and quantum criticality in dimerized antiferromagnets

In certain Mott-insulating dimerized antiferromagnets, triplet excitations of the paramagnetic phase display both three-particle and four-particle interactions. When such a magnet undergoes a quantum phase transition into a magnetically ordered state, the three-particle interaction becomes part of the critical theory provided that the lattice ordering wave vector is zero. One microscopic example is the staggered-dimer antiferromagnet on the square lattice, for which deviations from O(3) universality have been reported in numerical studies. Using both symmetry arguments and microscopic calculations, we show that a nontrivial cubic term arises in the relevant order-parameter quantum field theory, and we assess its consequences using a combination of analytical and numerical methods. We also present finite-temperature quantum Monte Carlo data for the staggered-dimer antiferromagnet which complement recently published results. The data can be consistently interpreted in terms of critical exponents identical to that of the standard O(3) universality class, but with anomalously large corrections to scaling. We argue that the cubic interaction of critical triplons, although irrelevant in two spatial dimensions, is responsible for the leading corrections to scaling due to its small scaling dimension.

Chaotic thermalization in Yang-Mills-Higgs theory on a spacial lattice

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Localization of a Bose-Einstein-condensate vortex in a bichromatic optical lattice

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Localization of collisionally inhomogeneous condensates in a bichromatic optical lattice

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Localization of a Bose-Fermi mixture in a bichromatic optical lattice

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