Magnetic Properties and Strong-Coupling Corrections in an Ultracold Fermi Gas with Population Imbalance

We investigate magnetic properties of an ultracold Fermi gas with population imbalance. In the presence of population imbalance, the strong-coupling theory developed by Nozières and Schmitt-Rink (which is frequently referred to as the NSR theory, or Gaussian fluctuation theory) is known to give unph...

Full description

Saved in:
Bibliographic Details
Published in:Journal of low temperature physics 2013-05, Vol.171 (3-4), p.355-361
Main Authors: Kashimura, T., Watanabe, R., Ohashi, Y.
Format: Article
Language:English
Subjects:
Approximation
Characterization and Evaluation of Materials
Condensed Matter Physics
Crossovers
Fluctuation
Fluctuation theory
Gaussian
Low temperature physics
Magnetic Materials
Magnetic properties
Magnetism
Mathematical analysis
Physics
Physics and Astronomy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We investigate magnetic properties of an ultracold Fermi gas with population imbalance. In the presence of population imbalance, the strong-coupling theory developed by Nozières and Schmitt-Rink (which is frequently referred to as the NSR theory, or Gaussian fluctuation theory) is known to give unphysical results in the BCS-BEC crossover region. We point out that this problem comes from how to treat pseudogap effects originating from pairing fluctuations and many-body corrections to the spin susceptibility. We also clarify how to overcome this problem by including higher order fluctuations beyond the ordinary T -matrix approximation. Calculated spin susceptibility based on our extended T -matrix approximation agrees well with the recent experiment on a 6 Li Fermi gas.
ISSN:0022-2291
1573-7357
DOI:10.1007/s10909-012-0724-2