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Cooper pairing with finite angular momentum: BCS vs Bose limits

J. Quintanilla·B. L. Gyorffy
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Abstract

We revisit the old problem of exotic superconductivity as Cooper pairing with finite angular momentum emerging from a central potential. Based on some general considerations, we suggest that the phenomenonn is associated with interactions that keep electrons at some particular, finite distance (r_{0}), and occurs at a range of intermediate densities (n\sim 1/r_{0}^{3}). We discuss the ground state and the critical temperature in the framework of a standard functional-integral theory of the BCS to Bose crossover. We find that, due to the lower energy of two-body bound states with (l=0), the rotational symmetry of the ground state is always restored on approaching the Bose limit. Moreover in that limit the critical temperature is always higher for pairs with (l=0.) The breaking of the rotational symmetry of the continuum by the superfluid state thus seems to be a property of weakly-attractive, non-monotonic interaction potentials, at intermediate densities.

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J. Quintanilla, B. L. Gyorffy. 2003-04-21. Cooper pairing with finite angular momentum: BCS vs Bose limits. https://doi.org/10.1088/0305-4470%2F36%2F35%2F322

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