Quantum transition to supersolid phase

S. Saito, S. Kurihara, Y. Y. Suzuki

    Research output: Contribution to journalArticle

    Abstract

    We study a possible coexistence of superconducting state and charge density waves which, in a broad sense, might be called a supersolid phase. We investigate the infinite dimensional (d = ∞) attractive Hubbard model by applying a sublattice dependent Gutzwiller wave function gA DAgB DB|BCS〉 as a variational wave function describing the ground state. One may naively expect that the BCS superconducting state evolves continuously to the Bose-Einstein condensed state of bipolarons as the attractive interaction increases, as far as the system is dilute. However, we show that our variational wave function has lower energy than the simple BCS wave function for all electron densities and the interaction strengths. Our variational parameters increase (gA,B→∞) as we increase the interaction strength (U→∞). The energy gap turns out to be a mixture of s and extended-s waves. In the vicinity of half-filling, we find a quantum transition from a simple superconducting phase to a supersolid phase with increase of the electron density and/or the interaction strength.

    Original languageEnglish
    Pages (from-to)231-232
    Number of pages2
    JournalJournal of Superconductivity and Novel Magnetism
    Volume12
    Issue number1
    Publication statusPublished - 1999

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    Keywords

    • CDW
    • Coexistence
    • Hubbard model
    • Superconductivity
    • Supersolid

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics
    • Physics and Astronomy (miscellaneous)

    Cite this

    Saito, S., Kurihara, S., & Suzuki, Y. Y. (1999). Quantum transition to supersolid phase. Journal of Superconductivity and Novel Magnetism, 12(1), 231-232.