title: Commensurate magnetic excitations induced by band splitting and Fermi surface topology in n-type cuprates.
abstract: The antiferromagnetic correlation plays an important role in high-Tc superconductors. Considering this effect, the magnetic excitations in n-type cuprates near the optimal doping are studied within the spin-density-wave description. The magnetic excitations are commensurate in the low-energy regime and further develop into spin-wave-like dispersion at higher energy, consistent with the inelastic neutron scattering measurements. We clearly demonstrate that the commensurability originates from the band splitting and Fermi surface topology. The commensurability is a normal state property and has nothing to do with d-wave superconductivity. Our results strongly suggest the essential role of antiferromagnetic correlations in the cuprates.
authors.affiliation: National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: H Y
authors.initials: HY
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.forename: H Q
authors.initials: HQ
authors.lastname: Lin
authors.forename: C D
authors.initials: CD
authors.lastname: Gong