The BCS-BEC Crossover and Superconductivity in a Lattice Fermion Model with Hard Core Repulsion |
| A. Kujawa
Institute of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland |
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| We considered the BCS-BEC crossover at T=0 in the framework of a lattice fermion model (the extended Hubbard model). We analyzed the case of on-site hard core repulsion (U=∞) and intersite attraction (W<0) in a 3D system with extended s-wave pairing symmetry. The mechanisms of density-driven and attraction-strength-driven crossover were analyzed. We obtained the ground state phase diagram. The analyzed quantities are: chemical potential, order parameter, coherence length, and fraction of condensed particles. |
| DOI: 10.12693/APhysPolA.111.745 PACS numbers: 71.10.Fd, 74.20.Rp, 71.27.+a, 71.10.Hf |