High-Field Hall effect in electron-doped Pr 2- x Ce x CuO 4

1. High-Field Hall effect in electron-doped Pr2-xCexCuO4 Richard L. Greene, University of Maryland, DMR 0352735 Electron-doped cuprate (n-type) superconductors RE2-xCexCuO4 have been actively studied recently. Numerous experiments have shown that the n-type cuprates exhibit many distinct properties from their hole-doped counterparts. Understanding the origin of these distinctions is important for understanding the mechanism of high-Tc superconductivity. High magnetic field is a powerful tool for revealing features in electrical transport that are not observable in low field. We performed Hall effect measurements in pulsed magnetic field up to 58 T on Pr2-xCexCuO4 films. A strong non-linear field dependent Hall resistivity is found above the optimal doping in a certain temperature range, while the low field linearity persists up to 58 T in the underdoped region at all measured temperatures (see figure). Only linear effects are seen in p-type cuprates at all dopings. Concomitant with this, changes in the field dependence of longitudinalmagnetoresistance are found. Our results [1] imply that a quantum phase transition occurs under the superconductivity dome in electron-doped cuprates. A Fermi surface reconstruction model can be used to qualitatively explain these high-field results. 1. Pengcheng Li et al., Phys. Rev. Lett., 99, 047003 (2007) Hall resistivity ρxyversus magnetic field of Pr2-xCexCuO4 films (a) underdoped x=0.13, (b) overdoped x=0.17

2. High-Field Hall effect in electron-doped Pr2-xCexCuO4 Richard L. Greene, University of Maryland, DMR 0352735 Education Societal Impact One graduate student, Pengcheng Li, contributed to this work. Dr. Li has just completed his PhD thesis and he is looking for a postdoctoral position in the United States. An understanding of the mechanism causing high temperature superconductivity may enable the development of new materials that are superconducting above room temperature. This would have a large impact on electronic devices and electricity generation and distribution.