Vortices in low-density neutron matter and cold Fermi gases

Journal Article · 07 July 2019 · Physical Review. C

DOI: https://doi.org/10.1103/physrevc.100.014001 · OSTI ID:1650615

Madeira, Lucas ^[1]; Gandolfi, Stefano  ^[2]; Schmidt, Kevin E. ^[3]; Bagnato, Vanderlei S. ^[1]

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1. Univ. of Sao Paulo (Brazil)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
3. Arizona State Univ., Tempe, AZ (United States)

Cold gas experiments can be tuned to achieve strongly-interacting regimes such as that of low-density neutron matter found in neutron-stars' crusts. We report T=0 diffusion Monte Carlo results (i) for the ground state of both spin-1/2 fermions with short-range interactions and low-density neutron matter in a cylindrical container, and (ii) properties of these systems with a vortex line excitation. We calculate the equation of state for cold atoms and low-density neutron matter in the bulk systems, and we contrast it to our results in the cylindrical container. We compute the vortex line excitation energy for different interaction strengths, and we find agreement between cold gases and neutron matter for very low densities. We also calculate density profiles, which allow us to determine the density depletion at the vortex core, which depends strongly on the short-ranged interaction in cold atomic gases, but it is of ≈25% for neutron matter in the density regimes studied in this work. Our results can be used to constrain neutron matter properties by using measurements from cold Fermi gases experiments.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: National Science Foundation (NSF); Sao Paulo Research Foundation (FAPESP); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA); XSEDE
• Grant/Contract Number: 89233218CNA000001; AC02-05CH11231; AC52-06NA25396
• OSTI ID: 1650615
• Report Number(s): LA-UR--19-22360
• Journal Information: Physical Review. C, Journal Name: Physical Review. C Journal Issue: 1 Vol. 100; ISSN 2469-9985
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English