Abstract
Recently it has been shown that not only GdFeCo alloys exhibit single-pulse helicity-independent all-optical switching, but that this effect is also seen in Co/Gd bilayers. However, there have been no reports on the explicit time dynamics of the switching process in these bilayers as of yet. Furthermore, time-resolved measurements of switching of other materials are typically done with a constant applied field to reset the magnetization between consecutive pulses and thus ensure repeatable behavior. In this paper we experimentally resolve the explicit dynamics of the switching process in Co/Gd, and the influence of applied magnetic fields on the switching process. We observe that after a switch within several picoseconds, the magnetization switches back at a time scale of hundreds of picoseconds. This backswitch includes a strong dependence on the magnetic field strength even at subtesla fields, significantly smaller than the exchange fields that govern the switching dynamics. This surprising behavior is explained by a combination of longitudinal switching (on a picosecond timescale), precessional switching (on a nanosecond time scale), and domain-wall motion (on a timescale of 10ns and beyond). We discuss these different switching regimes and their relative importance using simple model calculations.
| Original language | English |
|---|---|
| Article number | 014429 |
| Number of pages | 8 |
| Journal | Physical Review B |
| Volume | 105 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Jan 2022 |
Bibliographical note
Funding Information:We thank G. Malinowski, J. Gorchon, and S. Mangin for their help and fruitful discussions during the visit of M.J.G.P. and we thank M. Beens for the help with the layered-M3TM. This work is part of the research programme of the Foundation for Fundamental Research on Matter (FOM), which is part of the Dutch Research Council (NWO).
Funding
We thank G. Malinowski, J. Gorchon, and S. Mangin for their help and fruitful discussions during the visit of M.J.G.P. and we thank M. Beens for the help with the layered-M3TM. This work is part of the research programme of the Foundation for Fundamental Research on Matter (FOM), which is part of the Dutch Research Council (NWO).