D. Blume

Universal properties of a trapped two-component fermi gas at unitarity.

We treat the trapped two-component Fermi system, in which unlike fermions interact through a two-body short-range potential having no bound state but an infinite scattering length. By accurately solving the Schrödinger equation for up to N=6 fermions, we show that no many-body bound states exist other than those bound by the trapping potential, and we demonstrate unique universal properties of the system: Certain excitation frequencies are separated by 2variant Plancks over 2piomega, the wave functions agree with analytical predictions and a virial theorem is fulfilled. Further calculations up to N=30 determine the excitation gap, an experimentally accessible universal quantity, and it agrees with recent predictions based on a density functional approach.

Energetics and structural properties of trapped two-component Fermi gases

Using two different numerical methods, we study the behavior of two-component Fermi gases interacting through short-range s-wave interactions in a harmonic trap. A correlated Gaussian basis-set expansion technique is used to determine the energies and structural properties, i.e., the radial one-body densities and pair distribution functions, for small systems with either even or odd

Scattering Length Instability in Dipolar Bose-Einstein Condensates

N

Energetics and structural properties of three-dimensional bosonic clusters near threshold

, as functions of the s-wave scattering length and the mass ratio

Dipolar Bose-Einstein condensates with dipole-dependent scattering length

\kappa

Tuning the Interactions of Spin-Polarized Fermions Using Quasi-One-Dimensional Confinement

of the two species. Particular emphasis is put on a discussion of the angular momentum of the system in the BEC-BCS crossover regime. At unitarity, the excitation spectrum of the four-particle system with total angular momentum L=0 is calculated as a function of the mass ratio

Quasi-One-Dimensional Bose Gases with a Large Scattering Length

\kappa

BEC-BCS crossover of a trapped two-component Fermi gas with unequal masses

. The results are analyzed from a hyperspherical perspective, which offers new insights into the problem. Additionally, fixed-node diffusion Monte Carlo calculations are performed for equal-mass Fermi gases with up to N=30 atoms. We focus on the odd-even oscillations of the ground state energy of the equal-mass unitary system having up to N=30 particles, which are related to the excitation gap of the system. Furthermore, we present a detailed analysis of the structural properties of these systems.

Interacting Fermions in Highly Elongated Harmonic Traps

We characterize zero-temperature dipolar Bose gases under external spherical confinement as a function of the dipole strength using the essentially exact many-body diffusion Monte Carlo (DMC) technique. We show that the DMC energies are reproduced accurately within a mean-field framework if the variation of the s-wave scattering length with the dipole strength is accounted for properly. Our calculations suggest stability diagrams and collapse mechanisms of dipolar Bose gases that differ significantly from those previously proposed in the literature.

Nondivergent pseudopotential treatment of spin-polarized fermions under one- and three-dimensional harmonic confinement

We treat three-dimensional bosonic clusters with up to