THE AC HALL-EFFECT IN HIGH-T-C SUPERCONDUCTORS

Far-infrared magnetotransmission measurements of normal-state YBa2Cu3O 7 thin films are discussed. The magneto-optical signals observed in ci rcularly polarized light are consistent with the ac Hall effect of hol es with a reduced scattering rate and an enhanced mass compared to the zero-held transport parameters. The results agree with a simple high- frequency extension of models which have been developed to explain the anomalous de Hall effect in the normal state of high-T-c superconduct ors in terms of two scattering rates. The Hall scattering rate 1/tau(H ) similar to T-n/W-s, where n greater than or equal to 2 and W-s congr uent to 120 K. These experiments provide new tests of the Fermi-liquid versus non-Fermi-liquid nature of these materials.