Precursor of superfluidity in a strongly interacting Fermi gas with negative effective range

2018/02/03 by Hiroyuki Tajima · 14 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Fermi Gamma-ray Space Telescope #Fermi gas #Materials science #Physics #Quantum mechanics #Quantum, superfluid, helium dynamics #Range (aeronautics) #Superfluidity #cond-mat.quant-gas #nucl-th

paper · pdf · doi:10.1103/physreva.97.043613

published in Physical Review A 97(4) (American Physical Society) · 21 pages, 8 figures

arxiv created 2018/02/03 · openalex created_date 2018/02/23 · openalex publication_date 2018/04/16 · arxiv updated 2018/04/25 · openalex updated_date 2026/08/05

Abstract

We investigate theoretically the effects of pairing fluctuations in an ultracold Fermi gas near a Feshbach resonance with a negative effective range. By employing a many-body T-matrix theory with a coupled fermion-boson model, we show that the single-particle density of states exhibits the so-called pseudogap phenomenon, which is a precursor of superfluidity induced by strong pairing fluctuations. We clarify the region where strong pairing fluctuations play a crucial role in single-particle properties, from the broad-resonance region to the narrow-resonance limit at the divergent two-body scattering length. We also extrapolate the effects of pairing fluctuations to the positive-effective-range region from our results near the narrow Feshbach resonance. Results shown in this paper are relevant to the connection between ultracold Fermi gases and low-density neutron matter from the viewpoint of finite-effective-range corrections.

Citations

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