Cluster dynamical mean field theory of quantum phases on a honeycomb lattice

Article

关键词: METAL-INSULATOR-TRANSITION;    INFINITE DIMENSIONS;    MOTT TRANSITION;    HUBBARD-MODEL;    SUPERCONDUCTIVITY;    FERMIONS;    SYSTEMS;    STATE;   

DOI  :  10.1103/PhysRevB.86.045105

来源: SCIE

【 摘 要 】

We report the cluster dynamical mean field theory calculations performed for the ground state of the half filled Hubbard model on a honeycomb lattice with exact diagonalization on the cluster-impurity solver. Through using elaborate numerical analytic continuation, we identify the existence of a spin liquid from the on-site interaction U = 0 to U-c (between 4.6t and 4.85t) with a smooth crossover correspondingly from the charge fluctuation dominating phase into the charge correlation dominating phase. The semimetallic state exits only at U = 0. We further find that the magnetic phase transition at Uc from the spin liquid to the Neel antiferromagnetic Mott insulating phase is a first-order quantum phase transition. We also show that the charge fluctuation plays a substantial role on keeping the spin liquid phase against the emergence of a magnetic order.

【 授权许可】

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