Energetics and Structural Properties of Trapped Two-Component Fermi Gases

Abstract

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 $N$, as functions of the s-wave scattering length and the mass ratio $\kappa$ 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 $\kappa$. 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.

22 pages, 21 figures

References in corpus (13)

• Observation of Bose-Einstein Condensation of Molecules
• Weakly bound dimers of fermionic atoms
• Local Density Functional Theory for Superfluid Fermionic Systems: The Unitary Gas
• Low-energy three-body dynamics in binary quantum gases
• Scattering Length Scaling Laws for Ultracold Three-Body Collisions
• Universal properties of a trapped two-component Fermi gas at unitarity
• Diatomic molecules in ultracold Fermi gases - Novel composite bosons
• Effective Theory for Trapped Few-Fermion Systems
• Unitary Fermi Gas in a Harmonic Trap
• Spectrum and Dynamics of the BCS-BEC crossover from a few-body perspective
• BEC-BCS Crossover of a Trapped Two-Component Fermi Gas with Unequal Masses
• Level crossing in the three-body problem for strongly interacting fermions in a harmonic trap
• Mixtures of ultracold fermions with unequal masses

Cited by in corpus (9)

• Superfluid Bose-Fermi mixture from weak-coupling to unitarity
• Virial theorems for trapped cold atoms
• Effective Nonlinear Schrödinger Equations for Cigar-Shaped and Disk-Shaped Fermi Superfluids at Unitarity
• Dimer-dimer collisions at finite energies in two-component Fermi gases
• Small mass- and trap-imbalanced two-component Fermi systems
• Shell-Model Monte Carlo Simulations of BCS-BEC Crossover in Few-Fermion Systems
• Cold Fermionic Atoms in Two-Dimensional Traps -- Pairing versus Hund's Rule
• Universal behavior of a trapped Fermi superfluid in the BCS-unitarity crossover
• The Trapped Polarized Fermi Gas at Unitarity