Ground state of a resonantly Interacting Bose gas

  title={Ground state of a resonantly Interacting Bose gas},
  author={Jeroen Diederix and T.C.F. Van Heijst and H. T. C. Stoof},
  journal={Physical Review A},
We show that a two-channel mean-field theory for a Bose gas near a Feshbach resonance allows for an analytic computation of the chemical potential, and therefore the universal constant β, at unitarity. To improve on this mean-field theory, which physically neglects condensate depletion, we study a variational Jastrow ansatz for the ground-state wave function and use the hypernetted-chain approximation to minimize the energy for all positive values of the scattering length. We also show that… 

Figures from this paper

Dark Solitons in the Unitary Bose Gas

By solving the 1D NPSE, an effective one-dimensional nonpolynomial Schrodinger equation for the axial dynamics of the bosonic system is derived which takes also into account the transverse dynamics.

Resummation of Infrared Divergencies in the Theory of Atomic Bose Gases

We present a general strong-coupling approach for the description of an atomic Bose gas beyond the Bogoliubov approximation, when infrared divergences start to occur that need to be resummed exactly.

An HNC Approach to Strongly Interacting Ultracold Bose Gases

We argue that the energy of a strongly interacting gas in the unitary limit is parametrized by a universal constant β. For fermions, this parameter is known, but not for bosons. Finding β for bosons

Quenched Dynamics of the Momentum Distribution of the Unitary Bose Gas

We study the quenched dynamics of the momentum distribution of a unitary Bose gas under isotropic harmonic confinement within a time-dependent density functional approach based on our recently

Resonantly Interacting Degenerate Bose Gas Oddities

The progression from two- through few- to many-body physics is an open and interesting question. Experiments that can test these theories must walk the fine line between cultivating a rich many-body

Observation of Efimov Molecules Created from a Resonantly Interacting Bose Gas.

By analyzing the decay dynamics of the molecular gas, it is shown that in addition to Feshbach dimers it contains Efimov trimers, which shows a density dependence due to inelastic atom-dimer collisions, in agreement with theoretical calculations.

Hyperspherical lowest-order constrained-variational approximation to resonant Bose-Einstein condensates

We study the ground state properties of a system of $N$ harmonically trapped bosons of mass $m$ interacting with two-body contact interactions, from small to large scattering lengths. This is

Experimental Studies of a Degenerate Unitary Bose Gas

Date The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned



Universality and stability for a dilute Bose gas with a Feshbach resonance

We study the bosonic atoms with a wide Feshbach resonance at zero temperature in terms of the renormalization group. We indicate that this system will always collapse in the dilute limit. On the side

Extreme tunability of interactions in a 7Li Bose-Einstein condensate.

The shallow zero crossing in the wing of the Feshbach resonance enables the determination of a as small as 0.01 Bohr radii, evidence of the weak anisotropic magnetic dipole interaction is obtained by comparison with different trap geometries for small a.

The Josephson frequency of resonantly coupled atomic and molecular condensates

Motivated by recent experiments (Claussen et al 2003 Preprint cond-mat/0302195) we investigate the magnetic-field dependence of the Josephson frequency of coherent atom–molecule oscillations near a

Equation of state of a Fermi gas in the BEC-BCS crossover: a quantum Monte Carlo study.

The equation of state of a two-component Fermi gas with attractive short-range interspecies interactions using the fixed-node diffusion Monte Carlo method and results show a molecular regime with repulsive interactions well described by the dimer-dimer scattering length.

Cold bose gases with large scattering lengths.

At high densities n>>a(-3), the energy per particle, chemical potential, and square of the sound speed are independent of the scattering length and proportional to n(2/3), as in Fermi systems.

Bragg spectroscopy of a strongly interacting 85Rb Bose-Einstein condensate.

Measurements of the excitation spectrum of a strongly interacting Bose-Einstein condensate use two-photon Bragg spectroscopy and a magnetic-field Feshbach resonance to reach a regime where quantum depletion and beyond mean-field corrections to the condensates chemical potential are significant.

Asymmetric two-component Fermion systems in strong coupling.

The phase structure of a dilute two-component Fermi system with attractive interactions as a function of the coupling and a finite number asymmetry or polarization is studied and a picture of weakly interacting quasiparticles emerges for modest polarizations.

Pairing and Phase Separation in a Polarized Fermi Gas

We report the observation of pairing in a gas of atomic fermions with unequal numbers of two components. Beyond a critical polarization, the gas separates into a phase that is consistent with a