Monte Carlo Simulations of the Unitary Bose Gas

Abstract

We investigate the zero-temperature properties of a diluted homogeneous Bose gas made of $N$ particles interacting via a two-body square-well potential by perfor ming Monte Carlo simulations. We tune the interaction strength to achieve arbitrary positive values of the scattering length and compute by Monte Carlo quadrature the energy per particle $E/N$ and the condensate fraction $N_0/N$ of this system by using a Jastrow ansatz for the many-body wave function which avoids the formation of the self-bound ground-state and describes instead a (metastable) gaseous state with uniform den sity. In the unitarity limit, where the scattering length diverges while the range of the inter-atomic potential is much smaller than the average distance between atoms, we find a finite energy per particle ($E/N=0.70{\hslash }^2(6{\pi }^{2}n{)}^{2/3}/2m$, with $n$ th e number density) and a quite large condensate fraction ($N_0/N=0.83$).

5 pages, 2 figures (submitted to Phys. Rev. Lett.)

References in corpus (2)

• Nonlinear Schroedinger equation for a superfluid Bose gas from weak coupling to unitarity: Study of vortices
• Ground State Properties of Cold Bosonic Atoms At Large Scattering Lengths

Cited by in corpus (14)

• Universal Scaling Laws in the Dynamics of a Homogeneous Unitary Bose Gas
• Ground-state properties of unitary bosons: from clusters to matter
• Weakly bound states of two- and three-boson systems in the crossover from two to three dimension
• Ground state of a homogeneous Bose gas of hard spheres
• Bunching, clustering, and the buildup of few-body correlations in a quenched unitary Bose gas
• Strong correlation effects in a two-dimensional Bose gas with quartic dispersion
• Temperature-dependence of small harmonically trapped atom systems with Bose, Fermi and Boltzmann statistics
• Path integral molecular dynamics for thermodynamics and Green's function of ultracold spinor bosons
• Are Quasiparticles and Phonons Identical in Bose--Einstein Condensates?
• Equation of state and contact of a strongly interacting Bose gas in the normal state
• Dark solitons in the unitary Bose gas
• Two-Step Production of Resonant Bose-Einstein Condensates
• Density functional theory of a trapped Bose gas with tunable scattering length: from weak-coupling to unitarity
• Liquid-solid transitions in the three-body hard-core model