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We review the stochastic Gross-Pitaevskii approach for non-equilibrium finite temperature Bose gases, focussing on the formulation of Stoof; this method provides a unified description of condensed and thermal atoms, and can thus describe…

Quantum Gases · Physics 2017-08-23 Stuart P. Cockburn , Nick P. Proukakis

The mean-field properties of finite-temperature Bose-Einstein gases confined in spherically symmetric harmonic traps are surveyed numerically. The solutions of the Gross-Pitaevskii (GP) and Hartree-Fock-Bogoliubov (HFB) equations for the…

Statistical Mechanics · Physics 2009-10-31 T. Bergeman , D. L. Feder , N. L. Balazs , B. I. Schneider

Following the idea of the density functional approach, we develop a generalized Bogoliubov theory of an interacting Bose gas confined in a one-dimensional harmonic trap, by using a local chemical potential - calculated with the Lieb-Liniger…

Quantum Gases · Physics 2024-08-26 Xiao-Long Chen , Yun Li , Hui Hu

Fluctuations of the number of condensed atoms in a finite-size, weakly interacting Bose gas confined in a box potential are investigated for temperatures up to the critical region. The canonical partition functions are evaluated using a…

Statistical Mechanics · Physics 2015-05-13 Z. Idziaszek , L. Zawitkowski , M. Gajda , K. Rzazewski

We study fluctuations of the number of Bose condensed atoms in weakly interacting homogeneous and trapped gases. For a homogeneous system we apply the particle-number-conserving formulation of the Bogoliubov theory and calculate the…

Statistical Mechanics · Physics 2009-11-10 Zbigniew Idziaszek

Recently, a Quantum Monte Carlo method alternative to the Path Integral Monte Carlo method was developed for the numerical solution of the N-boson problem; it is based on the stochastic evolution of classical fields. Here we apply it to…

Statistical Mechanics · Physics 2009-11-07 Iacopo Carusotto , Yvan Castin

The stochastic Gross-Pitaevskii equation and modified Popov theory are shown to provide an ab initio description of finite temperature, weakly-interacting two-dimensional Bose gas experiments. Using modified Popov theory, a systematic…

Quantum Gases · Physics 2013-05-30 S. P. Cockburn , N. P. Proukakis

We propose an efficient stochastic method to implement numerically the Bogolubov approach to study finite-temperature Bose-Einstein condensates. Our method is based on the Wigner representation of the density matrix describing the non…

Statistical Mechanics · Physics 2015-06-24 Alice Sinatra , Yvan Castin , Carlos Lobo

We present an ab initio stochastic method for calculating thermal properties of a trapped, 1D Bose-gas covering the whole range from weak to strong interactions. Discretization of the problem results in a Bose-Hubbard-like Hamiltonian,…

Statistical Mechanics · Physics 2009-11-10 B. Schmidt , L. I. Plimak , M. Fleischhauer

We present a Hartree-Fock-Bogoliubov (HFB) theoretical treatment of the two-dimensional trapped Bose gas and indicate how semiclassical approximations to this and other formalisms have lead to confusion. We numerically obtain results for…

Statistical Mechanics · Physics 2016-08-31 Christopher Gies , Brandon van Zyl , S. A. Morgan , D. A. W. Hutchinson

We have achieved the first full implementation of the stochastic projected Gross-Pitaevskii equation for a three-dimensional trapped Bose gas at finite temperature. Our work advances previous applications of this theory, which have only…

Quantum Gases · Physics 2012-12-04 S. J. Rooney , P. B. Blakie , A. S. Bradley

We derive and discuss the equations of motion for the condensate and its fluctuations for a dilute, weakly interacting Bose gas in an external potential within the self--consistent Hartree--Fock--Bogoliubov (HFB) approximation. Account is…

Condensed Matter · Physics 2009-10-28 Allan Griffin

We present a theory for the linear dynamics of a weakly interacting Bose gas confined inside a harmonic trap at finite temperature. The theory treats the motions of the condensate and of the non-condensate on an equal footing within a…

Statistical Mechanics · Physics 2007-05-23 Xia-Ji Liu , Hui Hu , A. Minguzzi , M. P. Tosi

We formulate a generalized self-consistent stochastic quantum kinetic theory for finite-temperature ultracold Bose gases interacting via a generic long-range interaction, applicable to a broad range of systems, by means of Keldysh…

Quantum Gases · Physics 2025-07-28 Nick P. Proukakis , Gerasimos Rigopoulos , Alex Soto

We obtain approximations for the time-independent Gross-Pitaevskii (GP) and complex GP equation in two and three spatial dimensions by generalizing the divergence-free WKB method. The results include an explicit expression of a uniformly…

Quantum Gases · Physics 2015-06-05 Hayder Salman

The dynamics of a trapped Bose-condensed gas at finite temperatures is described by a generalized Gross-Pitaevskii equation for the condensate order parameter and a semi-classical kinetic equation for the thermal cloud, solved using…

Statistical Mechanics · Physics 2009-11-07 B. Jackson , E. Zaremba

We develop a practical theoretical formalism for studying the critical properties of a trapped Bose-Einstein condensate using the projected Gross-Pitaevskii equation. We show that this approach allows us investigate the behavior of the…

Statistical Mechanics · Physics 2009-03-31 A. Bezett , P. B. Blakie

We extend the Projected Gross Pitaevskii equation formalism of Davis et al. [Phys. Rev. Lett. \bf{87}, 160402 (2001)] to the experimentally relevant case of harmonic potentials. We outline a robust and accurate numerical scheme that can…

Other Condensed Matter · Physics 2015-06-24 P. Blair Blakie , Matthew J. Davis

We review c-field methods for simulating the non-equilibrium dynamics of degenerate Bose gases beyond the mean-field Gross-Pitaevskii approximation. We describe three separate approaches that utilise similar numerical methods, but have…

A stochastic Gross-Pitaevskii equation is derived for partially condensed Bose gas systems subject to binary contact interactions. The theory we present provides a classical-field theory suitable for describing dissipative dynamics and…

Quantum Gases · Physics 2014-08-28 Ashton S. Bradley , P. Blair Blakie
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