Trapped two-component Fermi gases with up to six particles: Energetics, structural properties, and molecular condensate fraction
arXiv:1008.3191 · doi:10.1016/j.crhy.2010.11.010
Abstract
We investigate small equal-mass two-component Fermi gases under external spherically symmetric confinement in which atoms with opposite spins interact through a short-range two-body model potential. We employ a non-perturbative microscopic framework, the stochastic variational approach, and determine the system properties as functions of the interspecies s-wave scattering length a, the orbital angular momentum L of the system, and the numbers N1 and N2 of spin-up and spin-down atoms (with N1-N2 =0 or 1 and N < 7, where N=N1+N2). At unitarity, we determine the energies of the five- and six-particle systems for various ranges r0 of the underlying two-body model potential and extrapolate to the zero-range limit. These energies serve as benchmark results that can be used to validate and assess other numerical approaches. We also present structural properties such as the pair distribution function and the radial density. Furthermore, we analyze the one-body and two-body density matrices. A measure for the molecular condensate fraction is proposed and applied. Our calculations show explicitly that the natural orbitals and the momentum distributions of atomic Fermi gases approach those characteristic for a molecular Bose gas if the s-wave scattering length a, a>0, is sufficiently small.
21 pages, 15 figures; accepted for publication in special issue of CRAS
References in corpus (36)
- Many-Body Physics with Ultracold Gases
- Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
- Theory of ultracold Fermi gases
- Weakly bound dimers of fermionic atoms
- Generalized Virial Theorem and Pressure Relation for a strongly correlated Fermi gas
- Observation of an Efimov spectrum in an atomic system
- General coordinate invariance and conformal invariance in nonrelativistic physics: Unitary Fermi gas
- Universality in Three- and Four-Body Bound States of Ultracold Atoms
- Critical Temperature and Thermodynamics of Attractive Fermions at Unitarity
- Evidence for Universal Four-Body States Tied to an Efimov Trimer
- Universal Properties of the Four-Body System with Large Scattering Length
- Virial expansion for a strongly correlated Fermi gas
- The potential energy of a K Fermi gas in the BCS-BEC crossover
- Local Density Functional Theory for Superfluid Fermionic Systems: The Unitary Gas
- Exact quantum Monte Carlo study of one dimensional trapped fermions with attractive contact interactions
- Universal properties of a trapped two-component Fermi gas at unitarity
- Weakly Bound Cluster States of Efimov Character
- Diatomic molecules in ultracold Fermi gases - Novel composite bosons
- Effective Theory for Trapped Few-Fermion Systems
- Energetics and Structural Properties of Trapped Two-Component Fermi Gases
- Evolution from a Bose-Einstein condensate to a Tonks-Girardeau gas: An exact diagonalization study
- Four-boson scale near a Feshbach resonance
- Unitary Fermi Gas in a Harmonic Trap
- Virial theorems for trapped cold atoms
- 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
- Energetics and structural properties of three-dimensional bosonic clusters near threshold
- Level crossing in the three-body problem for strongly interacting fermions in a harmonic trap
- Energy spectrum of harmonically trapped two-component Fermi gases: Three- and Four-Particle Problem
- Universality of Brunnian (-body Borromean) four and five-body systems
- Illustration of universal relations for trapped four-fermion system with arbitrary s-wave scattering length
- Efimov Trimer Formation via Ultracold Four-body Recombination
- Small mass- and trap-imbalanced two-component Fermi systems
- Criterion for Bose-Einstein condensation in traps and self-bound systems
- Internal One-Particle Density Matrix for Bose-Einstein Condensates with Finite Number of Particles in a Harmonic Potential
- Trapped Bose gases with large positive scattering length
Cited by in corpus (20)
- Few-body physics with ultracold atomic and molecular systems in traps
- Resonantly Interacting Fermions In a Box
- Effective-Range Dependence of Resonantly Interacting Fermions
- Natural and unnatural parity states of small trapped equal-mass two-component Fermi gases at unitarity and fourth-order virial coefficient
- Lattice methods for strongly interacting many-body systems
- Lattice Monte Carlo calculations for unitary fermions in a harmonic trap
- Universal four-body states in heavy-light mixtures with positive scattering length
- Probing strongly interacting atomic gases with energetic atoms
- Universality of the unitary Fermi gas: A few-body perspective
- Trapped unitary two-component Fermi gases with up to ten particles
- Occupation numbers of the harmonically trapped few-boson system
- Few-body perspective of a quantum anomaly in two-dimensional Fermi gases
- Small two-component Fermi gases in a cubic box with periodic boundary conditions
- Cluster formation in two-component Fermi gases
- Coupled pair approach for strongly-interacting trapped fermionic atoms
- A new effective interaction for the trapped fermi gas: the BEC-BCS crossover
- Three-body contact for fermions. I. General relations
- Lattice methods and effective field theory
- When does a Fermi puddle become a Fermi sea? Emergence of pairing in two-dimensional trapped mesoscopic Fermi gases
- Universal noise and Efimov physics