Energy equilibration processes of electrons, magnons, and phonons at the femtosecond time scale.
We relate the energy dissipation processes at the femtosecond (electron-spin relaxation time tau el-sp) and nanosecond time scale (Gilbert relaxation taualpha) to the microscopic model proposed by Koopmans [Phys. Rev. Lett. 95, 267207 (2005)]. At both time scales, Elliot-Yafet scattering is proposed as the dominant contribution. We controllably manipulate the energy dissipation by transition metal doping (Pd) and rare earth doping (Dy) of a Permalloy film. While a change in taualpha of more than a factor of 2 is observed, tau el-sp remains constant. We explain the discrepancies as due to relaxation channels not considered in the model.
Walowski
J
J
IV, Physikalisches Institut, Universität Göttingen, Germany.
Müller
G
G
Djordjevic
M
M
Münzenberg
M
M
Kläui
M
M
Vaz
C A F
CA
Bland
J A C
JA