Ultrafast optical spin injection into image-potential states of Cu(001).
We report the observation of a net spin polarization in the n=1 image-potential state at the Cu(001) surface. The spin polarization is achieved by spin-selective multiphoton excitation of electrons from the spin-orbit split Cu d bands to the image-potential state using circularly polarized ultrafast light pulses. We show that by tuning the exciting photon energy, we can adjust the resonant coupling of the image-potential state to d bands of different double-group symmetry. This allows us to tune the spin polarization injected into the image-potential state.
Winkelmann
A
A
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale), Germany. winkelm@mpi-halle.mpg.de
Bisio
F
F
Ocaña
R
R
Lin
W-C
WC
Nývlt
M
M
Petek
H
H
Kirschner
J
J