title: Antiferromagnetic vortex core in Tl(2)Ba(2)CuO(6+delta) studied by nuclear magnetic resonance.
abstract: Spatially resolved NMR is used to probe the magnetism in and around vortex cores of nearly optimally doped Tl(2)Ba(2)CuO(6+delta) (T(c)=85 K). The NMR relaxation rate T(-1)1 at the 205Tl site provides direct evidence that the antiferromagnetic (AF) spin correlation is significantly enhanced in the vortex core region. In the core region Cu spins show a local AF ordering with moments parallel to the layers at T(N)=20 K. Above T(N) the core region is in the paramagnetic state which is a reminiscence of the state above the pseudogap temperature (T(*) approximately 120 K), indicating that the pseudogap disappears within cores.
authors.affiliation: Division of Physics, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kakuyanagi
authors.forename: K
authors.initials: K
authors.lastname: Kumagai
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
authors.forename: M
authors.initials: M
authors.lastname: Hasegawa