Coupled oscillator systems require oscillators with properties that heretofore have not been addressed in oscillator design. Specifically, one needs to achieve wide locking bandwidth-the counterpart to low Q if the os...
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Coupled oscillator systems require oscillators with properties that heretofore have not been addressed in oscillator design. Specifically, one needs to achieve wide locking bandwidth-the counterpart to low Q if the oscillator is based on a resonant circuit. This letter introduces an approach to design of wide locking bandwidth by dealing with oscillator design in a feedback format. The specific realization reported here employs a MMIC amplifier with transmission line feedback external to the MMIC. Reactive loads that are weakly coupled to the transmission line allow one to achieve wide locking bandwidth. Results for an implementation at K-alpha band are provided.
Linear magnetic dichroism is observed in spin-, time-, and energy-resolved two-photon photoemission from valence bands of epitaxial fcc cobalt on Cu(001). With image-potential states as spectator states we identify in...
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Linear magnetic dichroism is observed in spin-, time-, and energy-resolved two-photon photoemission from valence bands of epitaxial fcc cobalt on Cu(001). With image-potential states as spectator states we identify initial bulk and surface states with minority spin character as the source for dichroic intensities and apparent dichroic lifetimes. Excellent agreement with ab initio fully relativistic calculations of the cobalt fcc band structure allows us to precisely determine spin-orbit hybridization points close to the Fermi level. These spin hot spots enhance spin-flip scattering by several orders of magnitude and are therefore assumed to be crucial in ultrafast demagnetization.
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