Correlated singlet phase in the one-dimensional Hubbard-Holstein model

Article

关键词: T-J MODEL;    ELECTRON-PHONON INTERACTION;    MOLECULAR-CRYSTAL MODEL;    CHARGE-DENSITY WAVES;    SMALL POLARONS;    SUPERCONDUCTIVITY;    SYSTEMS;    TRANSITION;    MANGANITES;    INSULATOR;   

DOI  :  10.1103/PhysRevB.86.045110

来源: SCIE

【 摘 要 】

We show that a nearest-neighbor singlet phase results (from an effective Hamiltonian) for the one-dimensional Hubbard-Holstein model in the regime of strong electron-electron and electron-phonon interactions and under nonadiabatic conditions (t/omega(0) <= 1). By mapping the system of nearest-neighbor singlets at a filling N-p/N onto a hard-core-boson (HCB) t-V model at a filling N-p/(N - N-p), we demonstrate explicitly that superfluidity and charge density wave (CDW) occur mutually exclusively with the diagonal long range order manifesting itself only at one-third filling. Furthermore, we also show that the Bose-Einstein condensate (BEC) occupation number n(0) for the singlet phase, similar to the n(0) for a HCB tight binding model, scales as root N; however, the coefficient of root N in the n(0) for the interacting singlet phase is numerically demonstrated to be smaller.

【 授权许可】

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