Abstract
We investigate the effective interaction between Cooper-pair molecules in the strong-coupling BEC regime of a superfluid Fermi gas with a Feshbach resonance. Our work uses a path integral formulation and a renormalization group (RG) analysis of fluctuations in a single-channel model. We show that a physical cutoff energy ωc originating from the finite molecular binding energy is the key to understanding the interaction between molecules in the BEC regime. Our work thus clari.es recent results by showing that a M = 2aF is a bare molecular scattering length while a M = (0.6-0.75)aF is the low-energy molecular scattering length renormalized to include high-energy scattering up to ωc (here, aF is the scattering length between Fermi atoms). We also include many-body effects at finite temperatures. We find that aM is strongly dependent on temperature, vanishing at Tc, consistent with the earlier Bose gas results of Bijlsma and Stoof.
| Original language | English |
|---|---|
| Pages (from-to) | 2659-2662 |
| Number of pages | 4 |
| Journal | Journal of the Physical Society of Japan |
| Volume | 74 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 2005 Oct |
| Externally published | Yes |
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Keywords
- BCS-BEC crossover
- Cold Fermi gas
- Fermion superfluidity
ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Effective interaction between molecules in the strong-coupling BEC regime of a superfluid fermi gas. / Ohashi, Yoji.
In: Journal of the Physical Society of Japan, Vol. 74, No. 10, 10.2005, p. 2659-2662.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effective interaction between molecules in the strong-coupling BEC regime of a superfluid fermi gas
AU - Ohashi, Yoji
PY - 2005/10
Y1 - 2005/10
N2 - We investigate the effective interaction between Cooper-pair molecules in the strong-coupling BEC regime of a superfluid Fermi gas with a Feshbach resonance. Our work uses a path integral formulation and a renormalization group (RG) analysis of fluctuations in a single-channel model. We show that a physical cutoff energy ωc originating from the finite molecular binding energy is the key to understanding the interaction between molecules in the BEC regime. Our work thus clari.es recent results by showing that a M = 2aF is a bare molecular scattering length while a M = (0.6-0.75)aF is the low-energy molecular scattering length renormalized to include high-energy scattering up to ωc (here, aF is the scattering length between Fermi atoms). We also include many-body effects at finite temperatures. We find that aM is strongly dependent on temperature, vanishing at Tc, consistent with the earlier Bose gas results of Bijlsma and Stoof.
AB - We investigate the effective interaction between Cooper-pair molecules in the strong-coupling BEC regime of a superfluid Fermi gas with a Feshbach resonance. Our work uses a path integral formulation and a renormalization group (RG) analysis of fluctuations in a single-channel model. We show that a physical cutoff energy ωc originating from the finite molecular binding energy is the key to understanding the interaction between molecules in the BEC regime. Our work thus clari.es recent results by showing that a M = 2aF is a bare molecular scattering length while a M = (0.6-0.75)aF is the low-energy molecular scattering length renormalized to include high-energy scattering up to ωc (here, aF is the scattering length between Fermi atoms). We also include many-body effects at finite temperatures. We find that aM is strongly dependent on temperature, vanishing at Tc, consistent with the earlier Bose gas results of Bijlsma and Stoof.
KW - BCS-BEC crossover
KW - Cold Fermi gas
KW - Fermion superfluidity
UR - http://www.scopus.com/inward/record.url?scp=27144474592&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=27144474592&partnerID=8YFLogxK
U2 - 10.1143/JPSJ.74.2659
DO - 10.1143/JPSJ.74.2659
M3 - Article
AN - SCOPUS:27144474592
VL - 74
SP - 2659
EP - 2662
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 10
ER -