State-resolved ultrafast charge and spin dynamics in [Co/Pd] multilayers

Abstract

We use transient absorption spectroscopy with circularly polarized x-rays to detect laser-excited hole states below the Fermi level and compare their dynamics with that of unoccupied states above the Fermi level in ferromagnetic [Co/Pd] multilayers. While below the Fermi level an instantaneous and significantly stronger demagnetization is observed, above the Fermi level the demagnetization is delayed by 35+/-10 fs. This provides a direct visualization of how ultrafast demagnetization proceeds via initial spin-flip scattering of laser-excited holes to the subsequent formation of spin waves.

arXiv comment10 pages, 4 figures. The following article has been submitted to Applied Physics Letters. After it is published, it will be found at https://publishing.aip.org/resources/librarians/products/journals/

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Cited by in corpus (5)

• Spintronic Sources of Ultrashort Terahertz Electromagnetic Pulses
• Optically controlling the competition between spin flips and intersite spin transfer in a Heusler half-metal on sub-100 fs timescales
• Photon shot-noise limited transient absorption soft X-ray spectroscopy at the European XFEL
• Electronic origin of x-ray absorption peak shifts
• Femtosecond charge and spin dynamics in CoPt alloys