Triple sign reversal of the Hall effect in HgBa2CaCu2O6 thin films after heavy-ion irradiation

[摘要] The triple sign reversal in the mixed-state Hall effect has been observed in ion-irradiated HgBa2CaCu2O6 thin films. The negative dip at the third sign reversal is more pronounced for higher fields, which is opposite to the case of the first sign reversal near T-c in most high-T-c superconductors. These observations can be explained by a recent prediction in which the third sign reversal is attributed to the energy derivative of the density of states and to a temperature-dependent function related to the superconducting energy gap. These contributions prominently appear in cases where the mean free path is significantly decreased, such as our case of ion-irradiated thin films.

[关键词] QUASI-PARTICLE SPECTRA;MIXED-STATE;SCALING BEHAVIOR;II SUPERCONDUCTORS;COLUMNAR DEFECTS;SINGLE-CRYSTALS;VORTEX;YBA2CU3O7-DELTA;RESISTIVITY;DEPENDENCE