TY - JOUR
T1 - Magnetic properties and strong-coupling corrections in an ultracold fermi gas with population imbalance
AU - Kashimura, T.
AU - Watanabe, R.
AU - Ohashi, Y.
N1 - Funding Information:
Acknowledgements We would like to thank S. Watabe, Y. Endo, D. Inotani, and R. Hanai for useful discussions. Y.O. was supported by Grant-in-Aid for Scientific research from MEXT in Japan (22540412, 23104723, 23500056).
PY - 2013/5
Y1 - 2013/5
N2 - 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 6Li Fermi gas.
AB - 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 6Li Fermi gas.
KW - Population imbalance
KW - Strong-coupling effects
KW - Superfluidity
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U2 - 10.1007/s10909-012-0724-2
DO - 10.1007/s10909-012-0724-2
M3 - Article
AN - SCOPUS:84892960512
VL - 171
SP - 355
EP - 361
JO - Journal of Low Temperature Physics
JF - Journal of Low Temperature Physics
SN - 0022-2291
IS - 3-4
ER -