https://doi.org/10.1140/epjst/e2015-02387-9
Regular Article
Density functional theory of a trapped Bose gas with tunable scattering length: From weak-coupling to unitarity
1 Dipartimento di Fisica e Astronomia “Galileo Galilei” and CNISM, Università di Padova, via Marzolo 8, 35122 Padova, Italy
2 CNR-IOM Democritos, via Bonomea 265, 34136 Trieste, Italy
3 CNR-INO, via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
Received: 15 October 2014
Revised: 19 February 2015
Published online: 9 April 2015
We study an interacting Bose gas at T = 0 under isotropic harmonic confinement within Density Functional Theory in the Local Density approximation. The energy density functional, which spans the whole range of positive scattering lengths up to the unitary regime (infinite scattering length), is obtained by fitting the recently calculated Monte Carlo bulk equation of state [Phys. Rev. A 89, 041602(R) (2014)]. We compare the density profiles of the trapped gas with those obtained by MC calculations. We solve the time-dependent Density Functional equation to study the effect of increasing values of the interaction strength on the frequencies of monopole and quadrupole oscillations of the trapped gas. We find that the monopole breathing mode shows a non-monotonous behavior as a function of the scattering length. We also consider the damping effect of three-body losses on such modes.
© EDP Sciences, Springer-Verlag, 2015
