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arXiv · 0905.2165

Ground-state fidelity in the BCS-BEC crossover

A. Khan·P. Pieri
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Abstract

The ground-state fidelity has been introduced recently as a tool to investigate quantum phase transitions. Here, we apply this concept in the context of a crossover problem. Specifically, we calculate the fidelity susceptibility for the BCS ground-state wave function, when the intensity of the fermionic attraction is varied from weak to strong in an interacting Fermi system, through the BCS-BEC crossover. Results are presented for contact and finite-range attractive potentials and for both continuum and lattice models. We conclude that the fidelity susceptibility can be useful also in the context of crossover problems.

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A. Khan, P. Pieri. 2009-05-13. Ground-state fidelity in the BCS-BEC crossover. https://doi.org/10.1103/physreva.80.012303

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