Theory of ultracold atomic Fermi gases

Journal Article · Wed Oct 15 00:00:00 EDT 2008 · Reviews of Modern Physics

DOI:https://doi.org/10.1103/REVMODPHYS.80.1215· OSTI ID:22038463

Giorgini, Stefano; Pitaevskii, Lev P; Stringari, Sandro ^[1]

---

1. Dipartimento di Fisica, Universita di Trento and CNR-INFM BEC Center, I-38050 Povo, Trento (Italy)

The physics of quantum degenerate atomic Fermi gases in uniform as well as in harmonically trapped configurations is reviewed from a theoretical perspective. Emphasis is given to the effect of interactions that play a crucial role, bringing the gas into a superfluid phase at low temperature. In these dilute systems, interactions are characterized by a single parameter, the s-wave scattering length, whose value can be tuned using an external magnetic field near a broad Feshbach resonance. The BCS limit of ordinary Fermi superfluidity, the Bose-Einstein condensation (BEC) of dimers, and the unitary limit of large scattering length are important regimes exhibited by interacting Fermi gases. In particular, the BEC and the unitary regimes are characterized by a high value of the superfluid critical temperature, on the order of the Fermi temperature. Different physical properties are discussed, including the density profiles and the energy of the ground-state configurations, the momentum distribution, the fraction of condensed pairs, collective oscillations and pair-breaking effects, the expansion of the gas, the main thermodynamic properties, the behavior in the presence of optical lattices, and the signatures of superfluidity, such as the existence of quantized vortices, the quenching of the moment of inertia, and the consequences of spin polarization. Various theoretical approaches are considered, ranging from the mean-field description of the BCS-BEC crossover to nonperturbative methods based on quantum Monte Carlo techniques. A major goal of the review is to compare theoretical predictions with available experimental results.

• OSTI ID: 22038463
• Journal Information: Reviews of Modern Physics, Vol. 80, Issue 4; Other Information: (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6861
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BCS THEORY
BOSE-EINSTEIN CONDENSATION
COMPARATIVE EVALUATIONS
CRITICAL TEMPERATURE
FERMI GAS
FERMIONS
GROUND STATES
MAGNETIC FIELDS
MEAN-FIELD THEORY
MOMENT OF INERTIA
MONTE CARLO METHOD
RESONANCE
S WAVES
SCATTERING LENGTHS
SPIN ORIENTATION
SUPERFLUIDITY
THERMODYNAMICS
TRAPPING