Finite-temperature effects on the superfluid Bose–Einstein condensation of confined ultracold atoms in three-dimensional optical lattices

Polak, T. P.; Kopeć, T. K.

doi:10.1088/0953-4075/42/9/095302

Cited by 28 publications

(23 citation statements)

References 23 publications

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“…Mean-field theory has been used [37][38][39] to study different properties and to obtain the finite-T phase diagram in any dimension. Various other approximate methods have also been used to study the finite temperature BoseHubbard model 40,41 . We present here the QMC homogeneous finite-T phase diagram in the (µ/U, t/U ) plane valid for the first two commensurate filling lobes.…”

Section: Model and Computational Methodsmentioning

confidence: 99%

Finite-temperature study of bosons in a two-dimensional optical lattice

et al. 2011

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We use quantum Monte Carlo (QMC) simulations to study the combined effects of harmonic confinement and temperature for bosons in a two dimensional optical lattice. The scale invariant, finite temperature, state diagram is presented for the Bose-Hubbard model in terms of experimental parameters -the particle number, confining potential and interaction strength. To distinguish the nature of the spatially separated superfluid, Mott Insulator and normal Bose liquid phases, we examine the local density, compressibility, superfluid density and Green's function. In the annular superfluid rings, as the width of the ring decreases, the long range superfluid correlations start to deviate from an equivalent homogeneous 2D system. At zero temperature, the correlation decay is intermediate between 1D and 2D, while at finite temperature, the decay is similar to that in 1D at a much lower temperature. The calculations reveal shortcomings of the local density approximation (LDA) in describing superfluid properties of trapped bosons. We also present the finite temperature phase diagram for the homogeneous two dimensional Bose-Hubbard model. We compare our state diagram with the results of a recent experiment at NIST on a harmonically trapped 2D lattice [Phys. Rev. Lett. 105, 110401 (2010)], and identify a finite temperature effect in the experiment.

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Section: Model and Computational Methodsmentioning

confidence: 99%

Finite-temperature study of bosons in a two-dimensional optical lattice

et al. 2011

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“…Positions of the maxima of the momentum distribution are correctly recreated as well as the decay of the envelope of the TOF image substantiating choice of the module of the Wannier function in Eq. (20). For isotropic system, the time-of-flight patterns exhibit two minima located around the zero momentum at k = ± (π/4, π/4).…”

Section: Uniaxially Staggered Fluxmentioning

confidence: 92%

“…It is also a natural extension of the QR model that was used to describe the phase diagram, also in the presence of the artificial magnetic field [17][18][19]. The QR approach has been verified [20,21] using other methods, like Monte Carlo numerical calculations [22] and diagrammatic perturbation theory [23]. The QR phase diagrams were also analyzed in the context of an analytical works: mean-field theory [24] and Padé analysis [25].…”

Section: Introductionmentioning

confidence: 99%

Time-of-flight patterns of ultracold bosons in optical lattices in various Abelian artificial magnetic field gauges

Polak

Zaleski

2013

Phys. Rev. A

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We calculate the time-of-flight patterns of strongly interacting bosons confined in two-dimensional square lattice in the presence of an artificial magnetic field using quantum rotor model that is inherently combined with the Bogolyubov approach. We consider various geometries of the magnetic flux, which are expected to be realizable, or have already been implemented in experimental settings. The flexibility of the method let us to study cases of the artificial magnetic field being uniform, staggered or forming a checkerboard configuration. Effects of additional temporal modulation of the optical potential that results from application of Raman lasers driving particle transitions between lattice sites are also included. The presented time-of-flight patterns may serve as a verification of chosen gauge in experiments, but also provide important hints on unconventional, non-zero momentum condensates, or possibility of observing graphene-like physics resulting from occurrence of Dirac cones in artificial magnetic fields in systems of ultra-cold bosons in optical lattices. Also, we elucidate on differences between effects of magnetic field in solids and the artificial magnetic field in optical lattices, which can be controlled on much higher level leading to effects not possible in condensed matter physics.

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“…This crossover occurs when the typical energy of thermal excitations, k B T , is of the same order as the energy gap of the system. It becomes manifests in the gradually vanishing of the Mott lobes [43][44][45].…”

Section: Introductionmentioning

confidence: 99%

“…In the following we will focus on the finite temperature phase transition of the Bose-Hubbard system in three dimensions [28,29,[45][46][47]. The paper is organized as follows.…”

Section: Introductionmentioning

confidence: 99%

Large-coordination-number expansion of a lattice Bose gas at finite temperature

2016

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The expansion of the partition function for large coordination number Z is a long standing method and has formerly been used to describe the Ising model at finite temperatures. We extend this approach and study the interacting Bose gas at finite temperatures. An analytical expression for the free energy is derived which is valid for weakly interacting and strongly interacting bosons. The transition line which separates the superfluid phase from Mott insulating/normal gas phase is shown for fillings n = 1 and n = 2. For unit filling, our findings agree qualitatively with Quantum Monte-Carlo results. Contrary to the well-known mean-field result, the shift of the critical temperature in the weakly interacting regime is apparent.

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Finite-temperature effects on the superfluid Bose–Einstein condensation of confined ultracold atoms in three-dimensional optical lattices

Cited by 28 publications

References 23 publications

Finite-temperature study of bosons in a two-dimensional optical lattice

Finite-temperature study of bosons in a two-dimensional optical lattice

Time-of-flight patterns of ultracold bosons in optical lattices in various Abelian artificial magnetic field gauges

Large-coordination-number expansion of a lattice Bose gas at finite temperature

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