Mixed-State Hall Conductivity in High- T c Superconductors: Direct Evidence of Its Independence on Disorder

摘要: We studied the Hall effect in a ${\mathrm{Tl}}_{2}{\mathrm{Ba}}_{2}{\mathrm{CaCu}}_{2}{O}_{8}$ epitaxial film and an ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}$ single crystal mixed state before after irradiation with high energy Pb ions. Pinning enhancement due to irradiation-induced columnar defects leads decrease magnitude of longitudinal resistivities, but does not modify behavior conductivity. This result is valid independent sign pinned region (positive for negative ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}$). The present work proves straightforwardly that mixed-state conductivity depend on pinning strength, agreement theory. dual analog 2D electronic systems where resistivity remains unaffected by disorder.