Unusual 1/T3 temperature dependence of the Hall conductivity in YBa2Cu3O7-

Measurements of the Hall coefficient RH and resistivity a of YBa2Cu3O7 disclose anomalies in their temperature (T) dependences. The 1/RH vs T curve has a negative curvature, while da/dT displays a previously unreported step near 290 K. The Hall conductivity H follows an unusual 1/T3 dependence from 100 to 360 K. We contrast the results with predictions of conventional Bloch theory, and compare them with recent calculations based on large-U models. Implications for cyclotron damping at low T are discussed.