Nernst Effect in Electron-Doped Pr$_{2-x}$Ce$_{x}$CuO$_4$

TL;DR

This study measures the Nernst effect in electron-doped Pr$_{2-x}$Ce$_{x}$CuO$_4$ thin films, finding no anomalous effects above critical temperatures, supporting models based on fluctuations in hole-doped cuprates.

Contribution

It provides the first detailed Nernst effect measurements in electron-doped cuprates, showing conventional behavior and supporting fluctuation models.

Findings

No anomalous Nernst effect above T_c and H_c2 in electron-doped cuprates

H_c2(T) shows conventional temperature dependence

Energy gap decreases with doping, consistent with tunneling data

Abstract

The Nernst effect of Pr$_{2-x}$Ce$_{x}$CuO$_4$ (x=0.13, 0.15, and 0.17) has been measured on thin film samples between 5-120 K and 0-14 T. In comparison to recent measurements on hole-doped cuprates that showed an anomalously large Nernst effect above the resistive T$_c$ and H$_{c2}$ \cite{xu,wang1,wang2,capan}, we find a normal Nernst effect above T$_c$ and H$_{c2}$ for all dopings. The lack of an anomalous Nernst effect in the electron-doped compounds supports the models that explain this effect in terms of amplitude and phase fluctuations in the hole-doped cuprates. In addition, the H$_{c2}$(T) determined from the Nernst effect shows a conventional behavior for all dopings. The energy gap determined from H$_{c2}$(0) decreases as the system goes from under-doping to over-dopingin agreement with the recent tunnelling experiments.