Instabilities of interacting electrons on the triangular lattice

Article

关键词: 2-DIMENSIONAL HUBBARD-MODEL;    D-WAVE SUPERCONDUCTIVITY;    RESONATING VALENCE BONDS;    UNCONVENTIONAL SUPERCONDUCTIVITY;    HEISENBERG-MODEL;    STATES;    PHASE;    ANTIFERROMAGNET;    ORDER;   

DOI  :  10.1103/PhysRevB.68.104510

来源: SCIE

【 摘 要 】

Motivated by the recent finding of superconductivity in layered CoO2 compounds, we investigate superconducting and magnetic instabilities of interacting electrons on the two-dimensional triangular lattice. Using a one-loop renormalization-group scheme for weak- to moderate-coupling strengths, we find that for purely local interactions U>0 and small Fermi surfaces the renormalization-group flow remains bounded down to very low scales and no superconducting or other instabilities can be detected. Antiferromagnetic exchange interactions J generate a wide density region with a d(x)(2)-y(2)+id(xy)-wave superconducting instability similar to recent proposals for the strongly correlated t-J model. For larger Fermi-surface volumes the interactions flow to strong coupling also for purely local interactions U>0. We find a singlet-pairing instability in the vicinity of strong magnetic ordering tendencies at three wave vectors for the Van Hove filling.

【 授权许可】

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