Fermionic density functional at a Feshbach resonance

Journal Article · Tue May 15 00:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.75.052509· OSTI ID:20982517

Seidl, Michael; Bhaduri, Rajat K ^[1]

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1. Institute of Theoretical Physics, University of Regensburg, D-93040 Regensburg (Germany)

We consider a dilute gas of neutral unpolarized fermionic atoms at zero temperature. The atoms interact via a short-range (tunable) attractive interaction. We demonstrate analytically a curious property of the gas at unitarity. Namely, the correlation energy of the gas, evaluated by second-order perturbation theory, has the same density dependence as the first-order exchange energy, and the two almost exactly cancel each other at a Feshbach resonance irrespective of the shape of the potential, provided ({mu}r{sub s})>>1. Here ({mu}){sup -1} is the range of the two-body potential, and r{sub s} is defined through the number density, n=3/(4{pi}r{sub s}{sup 3}). The implications of this result for universality are discussed.

• OSTI ID: 20982517
• Journal Information: Physical Review. A, Vol. 75, Issue 5; Other Information: DOI: 10.1103/PhysRevA.75.052509; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOUND STATE
DENSITY
DENSITY FUNCTIONAL METHOD
ELECTRON CORRELATION
EXCHANGE INTERACTIONS
FERMIONS
INTERACTIONS
PERTURBATION THEORY
POTENTIALS
RESONANCE
TEMPERATURE ZERO K
TWO-BODY PROBLEM
UNITARITY