Itinerant ferromagnetism in a Fermi gas with contact interaction: Magnetic properties in a dilute Hubbard model

Abstract

Ground state properties of the repulsive Hubbard model on a cubic lattice are investigated by means of the auxiliary-field quantum Monte Carlo method. We focus on low-density systems with varying on-site interaction $U/t$, as a model relevant to recent experiments on itinerant ferromagnetism in a dilute Fermi gas with contact interaction. Twist-average boundary conditions are used to eliminate open-shell effects and large lattice sizes are studied to reduce finite-size effects. The sign problem is controlled by a generalized constrained path approximation. We find no ferromagnetic phase transition in this model. The ground-state correlations are consistent with those of a paramagnetic Fermi liquid.

4+ pages, 4 figures

References in corpus (5)

• Itinerant Ferromagnetism in a Fermi Gas of Ultracold Atoms
• Auxiliary-field quantum Monte Carlo calculations of molecular systems with a Gaussian basis
• Spatially inhomogeneous phase in the two-dimensional repulsive Hubbard model
• Bond breaking with auxiliary-field quantum Monte Carlo
• Correlation effects in the ground state of trapped atomic Bose gases