Momentum Distribution and Condensate Fraction of a Fermion Gas in the BCS-BEC Crossover

Journal Article · Fri Dec 02 00:00:00 EST 2005 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.95.230405· OSTI ID:20699632

Astrakharchik, G E ^[1]; Boronat, J; Casulleras, J ^[2]; Giorgini, S ^[3]

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1. Dipartimento di Fisica and BEC-INFM, Universita di Trento, I-38050 Povo (Italy)
2. Departament de Fisica i Enginyeria Nuclear, Campus Nord B4-B5, Universitat Politecnica de Catalunya, E-08034 Barcelona (Spain)
3. JILA, University of Colorado, Boulder, Colorado 80309-0440 (United States)

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 to Bose-Einstein condensate (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 pairs is calculated in the unitary limit and on both sides of the BCS-BEC crossover.

• OSTI ID: 20699632
• Journal Information: Physical Review Letters, Vol. 95, Issue 23; Other Information: DOI: 10.1103/PhysRevLett.95.230405; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
BCS THEORY
BOSE-EINSTEIN CONDENSATION
DENSITY MATRIX
FERMI GAS
FERMIONS
FOURIER TRANSFORMATION
MONTE CARLO METHOD
TWO-BODY PROBLEM