title: Generalized Elliott-Yafet theory of electron spin relaxation in metals: origin of the anomalous electron spin lifetime in MgB2.
abstract: The temperature dependence of the electron-spin relaxation time in MgB2 is anomalous as it does not follow the resistivity above 150 K; it has a maximum around 400 K and decreases for higher temperatures. This violates the well established Elliot-Yafet theory of spin relaxation in metals. The anomaly occurs when the quasiparticle scattering rate (in energy units) is comparable to the energy difference between the conduction and a neighboring bands. The anomalous behavior is related to the unique band structure of MgB2 and the large electron-phonon coupling. The saturating spin relaxation is the spin transport analogue of the Ioffe-Regel criterion of electron transport.
authors.affiliation: Budapest University of Technology and Economics, Institute of Physics and Condensed Matter Research Group of the Hungarian Academy of Sciences, H-1521 Budapest, Hungary. simon@esr.phy.bme.hu
authors.forename: F
authors.initials: F
authors.lastname: Simon
authors.forename: B
authors.initials: B
authors.lastname: Dóra
authors.forename: F
authors.initials: F
authors.lastname: Murányi
authors.forename: A
authors.initials: A
authors.lastname: Jánossy
authors.forename: S
authors.initials: S
authors.lastname: Garaj
authors.forename: L
authors.initials: L
authors.lastname: Forró
authors.forename: S
authors.initials: S
authors.lastname: Bud'ko
authors.forename: C
authors.initials: C
authors.lastname: Petrovic
authors.forename: P C
authors.initials: PC
authors.lastname: Canfield