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Quantum Phase Transition in Extended Attractive Hubbard Model

S. Saito·H. Yoshimoto·Y. Y. Suzuki·S. Kurihara
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Abstract

We have made a variational analysis on an evolution of superconductivity from weak to strong coupling regime. In contrast to a crossover without thermodynamic anomaly found in a dilute system, we show the existence of a quantum phase transition near half filling. The transition is driven by charge density waves instabilities. We have found that superconductivity and charge density waves coexist in the presence of a weak intersite repulsion. The ground state phase diagram is determined and the quantum phase transition is an attractive version of the Mott transition.

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S. Saito, H. Yoshimoto, Y. Y. Suzuki, S. Kurihara. 2000-02-19. Quantum Phase Transition in Extended Attractive Hubbard Model. https://arxiv.org/abs/cond-mat/0002288

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