Asymmetric Fermi superfluid with different atomic species in a harmonic trap

Journal Article · Thu Nov 15 04:00:00 EST 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.76.053621· OSTI ID:21028062

Pao, C -H; Wu, S -T; Yip, S -K ^[1]

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1. Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China)

We study the dilute fermion gas with pairing between two species and unequal concentrations in a harmonic trap using the mean-field theory and the local density approximation. We found that the system can exhibit a superfluid shell structure sandwiched by the normal fermions. This superfluid shell structure occurs if the mass ratio is larger than a certain critical value, which increases from the weak-coupling BCS region to the strong-coupling Bose-Einstein condensation (BEC) side. In the strong-coupling BEC regime, the radii of the superfluid phase are less sensitive to the mass ratios and are similar to the case of pairing with equal masses. However, the lighter leftover fermions are easier to mix with the superfluid core than the heavier ones. A partially polarized superfluid can be found if the majority fermions are lighter, whereas phase separation is still found if they are heavier.

• OSTI ID: 21028062
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 76; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
ASYMMETRY
BCS THEORY
BOSE-EINSTEIN CONDENSATION
DENSITY FUNCTIONAL METHOD
FERMI GAS
FERMIONS
MEAN-FIELD THEORY
PAIRING INTERACTIONS
STRONG-COUPLING MODEL
SUPERFLUIDITY
TRAPS