Hall angle and vortex phases in HgBa2Ca2Cu3O8+delta thin films

We investigated the magnetic-field dependence of the Hall angle (theta(H)) for HgBa2Ca2Cu3O8+delta thin films. We found that a crossover field H*, whi ch is obtained from the field dependence of tan theta(H), coincides with th e crossover line that is obtained for longitudinal transport and that divid es the thermally activated flux-flow region from the critical region. The e ffective activation energy U-e at the critical region increases very rapidl y with decreasing temperature. To clarify the details of the vortex phase d iagram in the H-T plane, we extensively studied the Hall angle and the effe ctive activation energy. In addition to the above two regions, the Hall ang le was studied in the free flux-flow region, and the measured Hall angle sa tisfied tan theta(H)(T,H)similar or equal to a(T)+b(T)H, where a(T) strongl y depended on T and b(T) showed a weak T dependence.