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Metal-insulator crossover in the Boson-Fermion model in infinite dimensions

J. -M. Robin·A. Romano·J. Ranninger
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Abstract

The Boson-Fermion model, describing a mixture of tightly bound electron pairs and quasi-free electrons hybridized with each other via a charge exchange term, is studied in the limit of infinite dimensions, using the Non-Crossing Approximation within the Dynamical Mean Field Theory. It is shown that a metal-insulator crossover, driven by strong pair fluctuations, takes place as the temperature is lowered. It manifests itself in the opening of a pseudogap in the electron density of states, accompanied by a corresponding effect in the optical and dc conductivity.

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J. -M. Robin, A. Romano, J. Ranninger. 1998-08-24. Metal-insulator crossover in the Boson-Fermion model in infinite dimensions. https://doi.org/10.1103/physrevlett.81.2755

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