title: Unconventional anomalous Hall effect enhanced by a noncoplanar spin texture in the frustrated Kondo lattice Pr2Ir2O7.
abstract: We have investigated the Hall effect in the geometrically frustrated Kondo lattice Pr2Ir2O7. In its spin-liquid-like paramagnetic regime, the Hall resistivity rho(xy) is found to increase logarithmically on cooling. Moreover, in this low temperature region, the field dependence of the Hall conductivity sigma(xy) shows a large enhancement up to 30 Omega(-1) cm(-1) as well as a nonmonotonic change with the magnetization. Our results are far different from the anomalous Hall effect due to the spin-orbit coupling observed in ordinary magnetic conductors. We discuss the possible spin-chirality effect in the Ir 5d conduction band due to the noncoplanar texture of Pr<111> Ising-like moments.
authors.affiliation: Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Machida
authors.forename: S
authors.initials: S
authors.lastname: Nakatsuji
authors.forename: Y
authors.initials: Y
authors.lastname: Maeno
authors.forename: T
authors.initials: T
authors.lastname: Tayama
authors.forename: T
authors.initials: T
authors.lastname: Sakakibara
authors.forename: S
authors.initials: S
authors.lastname: Onoda