Vortex-state complex Hall conductivity of superconducting YBa2Cu3O7-delta epitaxial films at radio frequencies

The vortex-state complex Hall conductivity (sigma(xy)) of superconducting Y Ba2Cu3O7 epitaxial films is investigated from de to radio frequencies (up t o7 x 10(6)Hz), using a direct transport measurement technique. The experime ntal results are analyzed in terms of a model generalized from that for the de Hall conductivity. This generalized model assumes that (1) the occurren ce of sign revers;cll in the de vortex-state Hall conductivity is the resul t of different carrier densities within and Ear away from the vortex core; (2) the Drude approximation is applicable; and (3) the anomalous sign rever sal occurs in the Aux-flow limit. We. find that the temperature and frequen cy dependencies of our compiler Hall conductivity data are in good agreemen t with our phenomenological model. In addition, when extended to higher fre quencies, the same model provides consistent description for the complex Ha ll conductivity data at 100-800 GHz. Moreover, the magnetic-field (B) depen dence of the complex Hall conductivity data reveals that both vortices (sig ma(xy)(upsilon)) and quasiparticles (sigma(xy)(q)) contribute to the vortex -state Hall conduction, where sigma(xy)(upsilon)proportional to B-1 and sig ma(xy)(q)proportional to B, in agreement with the model. The magnitude of t he real part, sigma(xy)', is also consistent with the theoretical estimate, while the magnitude of the imaginary part, sigma(xy)" is significantly lar ger than the theoretical prediction, This discrepancy may be attributed to the unconventional electronic structures in vortices of cuprate: supercondu ctors with d-wave or mixed-pairing symmetries. [S0163-1829(99)05225-X].