2021/10/31 by Lin Sun, Jibiao Wang, Xiang Chu +1 · 4 citations
Chemistry · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Electron #Fermi Gamma-ray Space Telescope #Fermi gas #Lattice (music) #Mixing (physics) #Optical lattice #Pairing #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spectroscopy and Laser Applications #Superconductivity #Superfluidity #cond-mat.quant-gas #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1002/andp.202100511
published in Annalen der Physik 534(4) (Wiley) · 6 pages, 5 figures in color
openalex publication_date 2022/02/23 · arxiv created 2022/02/28 · arxiv updated 2022/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the superfluid behavior of ultracold atomic Fermi gases with a short range attractive interaction in a two-dimensional optical lattice (2DOL) using a pairing fluctuation theory, within the context of BCS-BEC crossover. We find that the mixing of lattice and continuum dimensions leads to exotic phenomena. For relatively large lattice constant d and small hopping integral t, the superfluid transition temperature Tc exhibits a remarkable reentrant behavior as a function of the interaction strength, and leads to a pair density wave ground state, where Tc vanishes, for a range of intermediate coupling strength. In the unitary and BCS regimes, the nature of the in-plane and overall pairing changes from particle-like to hole-like, with an unexpected nonmonotonic dependence of the chemical potential on the pairing strength. The BEC asymptotic behaviors exhibit distinct power law dependencies on the interaction strength compared to cases of pure 3D lattice, 3D continuum, and 1DOL. These predictions can be tested in future experiments.