Ultrafast Double Pulse All-Optical Reswitching of a Ferrimagnet
| Autor: | S. Lenne, Karsten Rode, Chandrima Banerjee, J. M. D. Coey, Gwenael Atcheson, Jean Besbas, Plamen Stamenov |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Condensed Matter - Materials Science Angular momentum Spins Condensed matter physics Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences General Physics and Astronomy Time trajectory State (functional analysis) 01 natural sciences Double pulse All optical Ferrimagnetism 0103 physical sciences Condensed Matter::Strongly Correlated Electrons 010306 general physics Ultrashort pulse |
| Zdroj: | Physical Review Letters. 126 |
| ISSN: | 1079-7114 0031-9007 |
| DOI: | 10.1103/physrevlett.126.177202 |
| Popis: | All-optical re-switching has been investigated in the half-metallic Heusler ferrimagnet Mn2Ru0.9Ga, where Mn atoms occupy two inequivalent sites in the XA-type structure. The effect of a second 200 fs 800 nm pump pulse that follows a first pulse, when both are above the threshold for switching, is studied as a function of t12, the time between them. The aims are to identify the physical mechanisms involved and to determine the minimum time needed for re-switching. The time trajectory of the switching process on a plot of sublattice angular momentum, S4a vs S4c, is in three stages; When t < 0.1 ps, the sublattice moments are rapidly disordered, but not destroyed, while conserving net angular momentum via optical spin-wave excitations. This leads to transient parallel alignment of the residual Mn spins in the first quadrant. The net angular momentum associated with the majority sublattice then flips in about 2 ps, and a fully-reversed ferrimagnetic state is then established via the spin-lattice interaction, which allows re-switching provided t12 > 10 ps. 13 pages - 4 figures |
| Databáze: | OpenAIRE |
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