| Popis: |
We discuss the Hall effect and resistivity above ${\mathit{T}}_{\mathit{c}}$, using a variant of the bipolaron theory which takes into account Anderson localization of the bosons by disorder. The model supposes that ${\mathit{R}}_{\mathit{H}}$=1/2${\mathit{en}}_{\mathit{b}}$c, where ${\mathit{n}}_{\mathit{b}}$ is the number of delocalized carriers. Temperature and doping dependences of \ensuremath{\rho}, ${\mathit{R}}_{\mathit{H}}$, cot${\mathrm{\ensuremath{\theta}}}_{\mathit{H}}$, and the ``spin'' gap in ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ are explained. |
