Carrier concentration independent antiferromagnetic spin fluctuations in the electron-doped high-temperature superconducting cuprate Pr2-xCexCuO4
UNSPECIFIED. (2004) Carrier concentration independent antiferromagnetic spin fluctuations in the electron-doped high-temperature superconducting cuprate Pr2-xCexCuO4. PHYSICAL REVIEW B, 69 (13). -. ISSN 1098-0121Full text not available from this repository.
Official URL: http://dx.doi.org/10.1103/PhysRevB.69.134504
We have performed Cu-63 NMR measurements on the electron-doped high-temperature superconducting cuprate (HTSC) Pr2-xCexCuO4 (x=0.10, 0.15, and 0.20), at 9 T, which is sufficient to suppress T-c to zero. The Cu spin-lattice relaxation rate and the Cu spin-lattice relaxation rate anisotropy can be consistently interpreted in terms of coupling to antiferromagnetic spin fluctuations for temperatures as low as 6 K. We find that the spin-fluctuation spectrum probed by the Cu spin-lattice relaxation rate does not change with increasing electronic concentration, contrary to a recent theoretical predication. There is no evidence in the Cu spin-lattice relaxation rate data for a temperature-independent spin gap that is as large as theoretically predicted or as large as the normal-state pseudogap energy reported from infrared reflectance measurements on the electron-doped HTSC Nd2-xCexCuO4. The Cu nuclear quadrupole resonance frequency is significantly smaller than that observed in the hole doped HTSC, which implies a nearly complete cancellation of the Cu 3d, O 2p, and nuclei contributions to the electric-field gradient at the Cu nucleus. The orbital shift anisotropy is similar to that observed in the hole doped HTSC, implying a similar relative splitting of the Cu 3d orbitals.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||PHYSICAL REVIEW B|
|Publisher:||AMERICAN PHYSICAL SOC|
|Number of Pages:||8|
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