Pairing with Unconventional Symmetry around BCS-BEC Crossover: Fermionic Atoms in 2D Optical Lattices to Correlated Electron Systems

2007/09/28 by Volcko, Dusan, Quader, Khandker F.
#FOS: Physical sciences #Other Condensed Matter (cond-mat.other) #Superconductivity (cond-mat.supr-con)

paper · doi:10.48550/arxiv.0710.0023

Abstract

We study superfluid properties of fermions on a 2D lattice using a finite-range pairing interaction derivable from an extended Hubbard model. We obtain signatures of unconventional pair-symmetry states, d_x²-y² and extended-s (s^*), in the BCS-BEC crossover region. The fermion momentum distribution function, v_k², the ratio of the Bogoliubov coefficients, v_k/u_k, and the Fourier transform of v_k² are among the properties that are strikingly different for d- and s^* symmetries in the crossover region. Fermionic atoms in 2D optical lattices may provide a way to observe these signatures. We discuss possible experimental ramifications of our results.

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