Numerical study of unitary fermions in one spatial dimension

Abstract

I perform lattice Monte Carlo studies of universal four-component fermion systems in one spatial dimension. Continuum few-body observables (i.e., ground-state energies and integrated contact densities) are determined for both unpolarized and polarized systems of up to eight fermions confined to a harmonic trap. Estimates of the continuum energies for four and five trapped fermions show agreement with exact analytic calculations to within approximately one percent statistical uncertainties. Continuum many-body observables are determined for unpolarized systems of up to 88 fermions confined to a finite box, and 56 fermions confined to a harmonic trap. Results are reported for universal quantities such as the Bertsch parameter, defined as the energy of the untrapped many-body system in units of the corresponding free-gas energy, and its subleading correction at large but finite scattering length. Two independent estimates of these quantities are obtained from thermodynamic limit extrapolations of continuum extrapolated observables. A third estimate of the Bertsch parameter is obtained by combining estimates of the untrapped and trapped integrated contact densities with additional theoretical input from a calculation based on Thomas-Fermi theory. All estimates of the Bertsch parameter and its subleading correction are found to be consistent to within approximately one percent statistical uncertainties. Finally, the continuum restoration of virial theorems is verified for both few- and many-body systems confined to a trap.

28 pages, 6 figures, 5 tables; Introduction rewritten, minor typos fixed, figures removed

References in corpus (14)

• Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas
• Generalized Virial Theorem and Pressure Relation for a strongly correlated Fermi gas
• General coordinate invariance and conformal invariance in nonrelativistic physics: Unitary Fermi gas
• Nonrelativistic conformal field theories
• Exact Relations for a Strongly-interacting Fermi Gas from the Operator Product Expansion
• Auxiliary Field quantum Monte Carlo for Strongly Paired Fermions
• Universal Fermi gases in mixed dimensions
• Exact Relations for a Strongly-interacting Fermi Gas near a Feshbach Resonance
• Lattice Monte Carlo calculations for unitary fermions in a finite box
• Density-functional theory for fermions in the unitary regime
• On Non-Relativistic Conformal Field Theory and Trapped Atoms: Virial Theorems and the State-Operator Correspondence in Three Dimensions
• Effective theory for the Goldstone field in the BCS-BEC crossover at T=0
• Lattice theory for nonrelativistic fermions in one spatial dimension
• Transdimensional equivalence of universal constants for Fermi gases at unitarity

Cited by in corpus (3)

• Complex Langevin and other approaches to the sign problem in quantum many-body physics
• Thermodynamics and static response of anomalous 1D fermions via quantum Monte Carlo in the worldline representation
• Few-body physics on a space-time lattice in the worldline approach