ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
With pulsed lasers as light sources, a new and important element is added to photoemission: time resolution. In order to make use of the high light intensities available, the experiment should measure the spin polarization of the total photoyield since this quantity is insensitive to space-charge effects. The following examples are discussed: (1) For amorphous GdTbFe, a magneto-optical storage material, it is shown that the speed of thermomagnetic writing critically depends on whether the initial temperature of the sample is above or below the compensation temperature. (2) The response of the magnetic order to pico- and nanosecond heating pulses has been measured in iron and other materials. It is found that the spin polarization of the electrons emitted from Fe by 30-ps pulses does not depend on the pulse energy even if melting occurs. Accordingly, ferromagnetic relaxation in Fe takes place on a time scale which is considerably longer than 30 ps. (3) Using optical spin orientation, the dynamics of the band bending induced by high-intensity laser pulses has been studied in a p-GaAs/Cs Schottky barrier. The buildup time for the photovoltage created by the electron-hole pairs excited in the band-bending region is of the order of several hundred picoseconds.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.348152
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