UNIVERSAL CONDUCTIVITY IN THE 2-DIMENSIONAL BOSON HUBBARD-MODEL

Article

关键词: SUPERCONDUCTOR-INSULATOR TRANSITION;    QUANTUM MONTE-CARLO;    PATH-INTEGRAL COMPUTATION;    DIMENSIONAL METALS;    SYSTEMS;    FILMS;    LOCALIZATION;    SIMULATIONS;    DISORDER;    RESISTANCE;   

DOI  :  10.1103/PhysRevB.48.9628

来源: SCIE

【 摘 要 】

We use quantum Monte Carlo methods to evaluate the conductivity sigma of the two-dimensional disordered boson Hubbard model at the superfluid-Bose-glass phase boundary. At the critical point for particle density rho = 0.5, we find sigma(c) = (0.45+/-0.07)sigma(Q), where sigma(Q) = e*2/h from a finite-size scaling analysis of the superfluid density. We obtain sigma(c) = (0.47+/-0.08)sigma(Q) from a direct calculation of the current-current correlation function. Simulations at the critical points for other particle densities, rho = 0.75 and 1.0, give similar values for sigma. We discuss possible origins of the difference in this value from that recently obtained by other numerical approaches.

【 授权许可】

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