The interplay between the magnetism and the high-T c superconductivity is one of the central issues for elucidating the pairing mechanism. For the hole-doped system it is now established that the spin fluctuations closely correlate with the superconductivity. Although the comparable study for hole- and electron-doped system is indispensable for the unified understanding of high-T c mechanism, many key experiments have been lacking for the electron-doped system. This is possibly due to the difficulty in preparing high-quality single crystal. Therefore, the universal magnetic properties of high-T c cuprates irrespective of the type of carriers are still controversial. To make a progress in the study of spin correlation in the electron-doped system, we have carried out a comprehensive neutron-scattering experiment on Pr 1-xLaCe xCuO 4, of which single crystal was successfully grown in our group for the first time. In this paper, we present the results of neutron-scattering study on the spin fluctuations as a function of doping and energy transfer. The degradation of doping evolution of low-energy spin fluctuations in the superconducting phase and the characteristic dual nature of spin excitation spectrum in the optimally and overdoped samples are introduced.
- Electron-dope high-T superconductor
- Neutron-scattering measurements
- Spin correlations