We have studied the nonlinear current-voltage characteristic of a two dimensional lattice Coulomb gas by Monte Carlo simulation. We present three different determinations of the power-law exponent $a(T)$ of the nonlinear current-voltage characteristic, $V

MonteCarlocalculationofthecurrent-voltagecharacteristicsofa

twodimensionallatticeCoulombgas

HansWeber1,MatsWallin2,andHenrikJeldtoftJensen3

1DepartmentofPhysics,Lule aUniversityofTechnology,S-97187Lule a,Sweden

arXiv:cond-mat/9601040v1 13 Jan 19962DepartmentofTheoreticalPhysics,RoyalInstituteofTechnology,S-10044Stockholm,SwedenofMathematics,ImperialCollage,LondonSW72BZ,UnitedKingdom3DepartmentAbstractWehavestudiedthenonlinearcurrent-voltagecharacteristicofatwodimen-sionallatticeCoulombgasbyMonteCarlosimulation.Wepresentthreedi erentdeterminationsofthepower-lawexponenta(T)ofthenonlinearcurrent-voltagecharacteristic,V～Ia(T)+1.Thedeterminationsrelyonbothequilibriumandnon-equilibriumsimulations.We ndgoodagreementbe-tweenthedi erentdeterminations,andourresultsalsoagreecloselywithexperimentalresultsforHg-Xethin lmsuperconductorsandforcertainsin-glecrystalthin- lmhightemperaturesuperconductors.

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