Normal-state Nernst effect in aTl2Ba2CaCu2O8+δepitaxial film

We report a measurement of the Nernst effect in the normal state of a cuprate superconductor, ${\mathrm{Tl}}_2$ ${\mathrm{Ba}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{8+\mathrm{\delta }}$, over the temperature range from ${\mathit{T}}_{\mathit{c}}$ to above room temperature. The signal is small: the Nernst coefficient, Q, is never larger than 3 nV/K T over the entire temperature range. The negative sign of Q suggests that the cyclotron scattering rate, 1/${\mathrm{\tau }}_{\mathit{H}}$, increases with particle energy in ${\mathrm{Tl}}_2$ ${\mathrm{Ba}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{8+\mathrm{\delta }}$.