title: Curie point singularity in the temperature derivative of resistivity in (Ga,Mn)As.
abstract: We observe a singularity in the temperature derivative drho/dT of resistivity at the Curie point of high-quality (Ga,Mn)As ferromagnetic semiconductors with Tc's ranging from approximately 80 to 185 K. The character of the anomaly is sharply distinct from the critical contribution to transport in conventional dense-moment magnetic semiconductors and is reminiscent of the drho/dT singularity in transition metal ferromagnets. Within the critical region accessible in our experiments, the temperature dependence on the ferromagnetic side can be explained by dominant scattering from uncorrelated spin fluctuations. The singular behavior of drho/dT on the paramagnetic side points to the important role of short-range correlated spin fluctuations.
authors.affiliation: Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Novák
authors.forename: K
authors.initials: K
authors.lastname: Olejník
authors.forename: J
authors.initials: J
authors.lastname: Wunderlich
authors.forename: M
authors.initials: M
authors.lastname: Cukr
authors.forename: K
authors.initials: K
authors.lastname: Výborný
authors.forename: A W
authors.initials: AW
authors.lastname: Rushforth
authors.forename: K W
authors.initials: KW
authors.lastname: Edmonds
authors.forename: R P
authors.initials: RP
authors.lastname: Campion
authors.forename: B L
authors.initials: BL
authors.lastname: Gallagher
authors.forename: Jairo
authors.initials: J
authors.lastname: Sinova
authors.forename: T
authors.initials: T
authors.lastname: Jungwirth