Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ground-state energy, density profiles, and momentum distribution of
  attractively interacting 1D Fermi gases with hard-wall boundaries: a Monte
  Carlo study   Motivated by the realization of hard-wall boundary conditions in experiments
with ultracold atoms, we investigate the ground-state properties of spin-1/2
fermions with attractive interactions in a one-dimensional box. We use lattice
Monte Carlo methods to determine essential quantities like the energy, which we
compute as a function of coupling strength and particle number in the regime
from few to many particles. Many-fermion systems bound by hard walls display
non-trivial density profiles characterized by so-called Friedel oscillations
(which are similar to those observed in harmonic traps). In non-interacting
systems, the characteristic length scale of the oscillations is set by (2
kF)^(-1), where kF is the Fermi momentum, while repulsive interactions tend to
generate Wigner-crystal oscillations of period (4 kF)^(-1). Based on the
non-interacting result, we find a remarkably simple parametrization of the
density profiles of the attractively interacting case, which we generalize to
the one-body density matrix. While the total momentum is not a conserved
quantity in the presence of hard walls, the magnitude of the momentum does
provide a good quantum number. We are therefore able to provide a detailed
characterization of the (quasi-)momentum distribution, which displays rather
robust discontinuity at the Fermi surface. In addition, we determine the
spatially varying on-site density-density correlation, which in turn yields
Tan's contact density and, upon integration, Tan's contact. As is well known,
the latter fully determines the short-range correlations and plays a crucial
role in a multitude of equilibrium and non-equilibrium sum rules.

30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio