Effective-range dependence of two-dimensional Fermi gases

Abstract

The Feshbach resonance provides precise control over the scattering length and effective range of interactions between ultracold atoms. We propose the ultratransferable pseudopotential to model effective interaction ranges $-1.5\le k_{\mathrm{F}}^2{R}_{\mathrm{eff}}^2\le 0$, here $R_{\mathrm{eff}}$ is the effective range and $k_{\mathrm{F}}$ is the Fermi wave vector, describing narrow to broad Feshbach resonances. We develop a mean-field treatment and exploit the pseudopotential to perform a variational and diffusion Monte Carlo study of the ground state of the two-dimensional Fermi gas, reporting on the ground-state energy, contact, condensate fraction, momentum distribution, and pair-correlation functions as a function of the effective interaction range across the BEC-BCS crossover. The limit $k_{\mathrm{F}}^2{R}_{\mathrm{eff}}^2\to -\infty$ is a gas of bosons with zero binding energy, whereas $\ln (k_{\mathrm{F}}a)\to -\infty$ corresponds to noninteracting bosons with infinite binding energy.

13 pages, 12 figures

References in corpus (14)

• Many-Body Physics with Ultracold Gases
• Generalized Virial Theorem and Pressure Relation for a strongly correlated Fermi gas
• Continuum variational and diffusion quantum Monte Carlo calculations
• Resonantly-paired fermionic superfluids
• Inhomogeneous backflow transformations in quantum Monte Carlo calculations
• Observation of a two-dimensional Fermi gas of atoms
• Exact Relations for a Strongly-interacting Fermi Gas near a Feshbach Resonance
• Effective-Range Dependence of Resonantly Interacting Fermions
• Superfluidity at the BEC-BCS crossover in two-dimensional Fermi gases with population and mass imbalance
• Berezinskii-Kosterlitz-Thouless transition in trapped quasi-two-dimensional Fermi gas near a Feshbach resonance
• Condensate Fraction of a Two-Dimensional Attractive Fermi Gas
• Effective-range dependence of resonant Fermi gases
• Quantum Monte Carlo calculation of the zero-temperature phase diagram of the two-component fermionic hard-core gas in two dimensions
• High-fidelity pseudopotentials for the contact interaction

Cited by in corpus (3)

• Brueckner $G$-matrix approach to two-dimensional Fermi gases with the finite-range attractive interaction
• Diffusion Monte Carlo study of a spin-imbalanced two-dimensional Fermi gas with attractive interactions
• Temporal fluctuation induced order in conventional superconductors