Anomalous normal state Nernst effect in electron doped Pr$_{2-x}$Ce$_{x}$CuO$_{4-y}$

We present systematic studies of the normal state Nernst effect in thin films of the electron doped superconductor Pr$_{2-x}$Ce$_{x} $CuO$_{4-y}$ (x=0.05, 0.11, 0.13, 0.15, 0.17, 0.19 and 0.21). A large \textbf{\textit{positive}} normal state Nernst signal appears at all doping levels with different magnitude and temperature dependence. The off-diagonal Peltier term $\alpha _{xy}$ is derived from the Nernst, resistivity and thermoelectric power and Hall effect, and its dependence on charge carrier density and relaxation time $\tau $ will be presented. Our results are compatible with a two band (ambipolar) model. Possible explanations for the temperature dependence of the Nernst effect will be presented. \textbf{(This work is supported by NSF Grant DMR-0352735)}