Nernst effect in electron-dopedPr2−xCexCuO4

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 c 2 [Z. A. Xu et al., Nature (London) 406, 486 (2000); Yayu Wang et al., Phys. Rev. B 64, 224519 (2001); Yayu Wang et al., Phys. Rev. Lett. 88, 257003 (2002); C. Capan et al., ibid. 88, 056601 (2002)], we find a normal Nernst effect above T c and H c 2 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 c 2 (T) determined from the Nernst effect shows a conventional behavior for all dopings. The energy gap determined from H c 2 (0) decreases as the system goes from underdoping to overdoping in agreement with the recent tunneling experiments.