Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 355-361 |
| Number of pages | 7 |
| Journal | Journal of Low Temperature Physics |
| Volume | 171 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 2013 |
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Keywords
- Population imbalance
- Strong-coupling effects
- Superfluidity
ASJC Scopus subject areas
- Condensed Matter Physics
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
Cite this
Magnetic properties and strong-coupling corrections in an ultracold fermi gas with population imbalance. / Kashimura, T.; Watanabe, R.; Ohashi, Yoji.
In: Journal of Low Temperature Physics, Vol. 171, No. 3-4, 2013, p. 355-361.Research output: Contribution to journal › Article
}
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, Yoji
PY - 2013
Y1 - 2013
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
UR - http://www.scopus.com/inward/record.url?scp=84892960512&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84892960512&partnerID=8YFLogxK
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 -