Novel interpretation of recent experiments on the dynamics of domain walls along ferrimagnetic strips

Abstract

Domain wall motion along ferrimagnets is evaluated using micromagnetic simulations and a collective-coordinates model, both considering two sublattices with independent parameters. Analytical expressions are derived for strips on top of either a heavy metal or a substrate with negligible interfacial Dzyaloshinskii-Moriya Interaction. The work focuses its findings in this latter case, with a field-driven domain wall motion depicting precessional dynamics which become rigid at the angular momentum compensation temperature, and a current-driven dynamics presenting more complex behavior, depending on the polarization factors for each sublattice. Importantly, our analyses provide also novel interpretation of recent evidence on current-driven domain wall motion, where walls move either along or against the current depending on temperature. Besides, our approach is able to substantiate the large non-adiabatic effective parameters found for these systems.

Elucidation of the mechanism for maintaining ultrafast domain wall mobility over a wide temperature range

“…They also observed a threshold in the case of T > T AMC . 27 Therefore, it was seen that the threshold in Gd 24 (Fe 88 Co 12 ) 76 at 30 and 3 ns corresponded to T > T AMC and T = T AMC , respectively. Therefore, the fast DW motion with linear dependency on the current density was obtained at 3 ns for Gd 24 (Fe 88 Co 12 ) 76 , which corresponds to the theoretical report.…”

“…They also observed a threshold in the case of T> T AMC 27 . Therefore, it is seen that the 9 As discussed previously, in ferrimagnetic materials the temperature can affect their magnetic properties 25 .…”