Asymmetric scattering of quasiparticles by pinned vortices in YBa2Cu3O7 produces an unusually large thermal Hall conductivity xy in the mixed state. In high fields, the xy vs field profile displays strong curvature, which allows the zero-field mean free path l0 of the quasiparticles to be determined. We find that l0 undergoes a remarkable increase from 90 near 90 K to 2500 at 15 K. The scattering rate changes by a factor of 3 between 90 and 75 K. We discuss implications for the scattering mechanism. From xy and l0, we obtain a new estimate of the thermal conductivity of in-plane quasiparticles.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)