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.
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale), Germany. winkelm@mpi-halle.mpg.de
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A
Winkelmann
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Bisio
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Ocaña
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WC
Lin
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Nývlt
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Petek
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Kirschner