Pinning, thermal fluctuation and Hall effect in the mixed state: a numerical study

Employing a single flux flow model by Wang, Dong and Ting, we investigate effects of pinning and thermal fluctuation on the negative Hall effect in the mixed-state by numerical methods. The simulation results indicate that both the pinning and the thermal fluctuation have a significant impact on the anomalous Hall effect. It is found that there exists an optimum pinning density for the maximum \rho(xy)\ of the negative Hall resistivity. The increase in the amplitude of each pinning potential well always intensifies the negative Hall effect. These results are well consistent with several recent experiments.