title: Novel in-gap spin state in Zn-doped La1.85Sr0.15CuO4.
abstract: Low-energy spin excitations of La(1.85)Sr(0.15)Cu(1-y)Zn(y)O4 were studied by neutron scattering. In y=0.004, the incommensurate magnetic peaks show a well-defined "spin gap" below T(c). The magnetic signals at omega=3 meV decrease below T(c)=27 K for y=0.008, also suggesting the gap opening. At lower temperatures, however, the signal increases again, implying a novel in-gap spin state. In y=0.017, the spin gap vanishes and elastic magnetic peaks appear. These results clarify that doped Zn impurities induce the novel in-gap state, which becomes larger and more static with increasing Zn.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan. kimura@tagen.tohokuu.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Kimura
authors.forename: M
authors.initials: M
authors.lastname: Kofu
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: K
authors.initials: K
authors.lastname: Hirota