TY - JOUR
T1 - Early Stages of Ultrafast Spin Dynamics in a 3d Ferromagnet
AU - Gort, R.
AU - Bühlmann, K.
AU - Däster, S.
AU - Salvatella, G.
AU - Hartmann, N.
AU - Zemp, Y.
AU - Holenstein, S.
AU - Stieger, C.
AU - Fognini, A.
AU - Michlmayr, T. U.
AU - Bähler, T.
AU - Vaterlaus, A.
AU - Acremann, Y.
PY - 2018
Y1 - 2018
N2 - Prior to the development of pulsed lasers, one assigned a single local temperature to the lattice, the electron gas, and the spins. With the availability of ultrafast laser sources, one can now drive the temperature of these reservoirs out of equilibrium. Thus, the solid shows new internal degrees of freedom characterized by individual temperatures of the electron gas Te, the lattice Tl and the spins Ts. We demonstrate an analogous behavior in the spin polarization of a ferromagnet in an ultrafast demagnetization experiment: At the Fermi energy, the polarization is reduced faster than at deeper in the valence band. Therefore, on the femtosecond time scale, the magnetization as a macroscopic quantity does not provide the full picture of the spin dynamics: The spin polarization separates into different parts similar to how the single temperature paradigm changed with the development of ultrafast lasers.
AB - Prior to the development of pulsed lasers, one assigned a single local temperature to the lattice, the electron gas, and the spins. With the availability of ultrafast laser sources, one can now drive the temperature of these reservoirs out of equilibrium. Thus, the solid shows new internal degrees of freedom characterized by individual temperatures of the electron gas Te, the lattice Tl and the spins Ts. We demonstrate an analogous behavior in the spin polarization of a ferromagnet in an ultrafast demagnetization experiment: At the Fermi energy, the polarization is reduced faster than at deeper in the valence band. Therefore, on the femtosecond time scale, the magnetization as a macroscopic quantity does not provide the full picture of the spin dynamics: The spin polarization separates into different parts similar to how the single temperature paradigm changed with the development of ultrafast lasers.
UR - http://resolver.tudelft.nl/uuid:07663baa-ec2c-41b1-bfef-7206b6bc5fd3
UR - http://www.scopus.com/inward/record.url?scp=85052232457&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.121.087206
DO - 10.1103/PhysRevLett.121.087206
M3 - Article
AN - SCOPUS:85052232457
SN - 0031-9007
VL - 121
JO - Physical Review Letters
JF - Physical Review Letters
IS - 8
M1 - 087206
ER -