Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Momentum distribution and condensate fraction of a Fermi gas in the
  BCS-BEC crossover   By using the diffusion Monte Carlo method we calculate the one- and two-body
density matrix of an interacting Fermi gas at T=0 in the BCS-BEC crossover.
Results for the momentum distribution of the atoms, as obtained from the
Fourier transform of the one-body density matrix, are reported as a function of
the interaction strength. Off-diagonal long-range order in the system is
investigated through the asymptotic behavior of the two-body density matrix.
The condensate fraction of fermionic pairs is calculated in the unitary limit
and on both sides of the BCS-BEC crossover.

35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
2
The categories of this paper are: math