Electric-field control of domain wall motion in perpendicularly magnetized materials

Abstract

Domain wall motion in materials exhibiting perpendicular magnetic anisotropy has been the subject of intensive research because of its large potential for future spintronic devices. Recently, it has been shown that perpendicular anisotropy of thin films can be influenced by electric fields. Voltage-controlled magnetic switching has already been realized, which is envisioned to lead to low-power logic and memory devices. Here we demonstrate a radically new application of this effect, namely control of domain wall motion by electric fields. We show that an applied voltage perpendicular to a Co or CoB wire can significantly increase or decrease domain wall velocities. Velocity modification over an order of magnitude is demonstrated (from 0.4 to 4 µm s − 1 ), providing a first step towards electrical control of domain wall devices. This opens up possibilities of real-time and local control of domain wall motion by electric fields at extremely low power cost.

Highly efficient voltage control of spin and enhanced interfacial perpendicular magnetic anisotropy in iridium-doped Fe/MgO magnetic tunnel junctions

“…5,6 The achievement of the VCMA effect in MgO-based MTJs 7 and the demonstration of high-speed responses, such as voltage-induced ferromagnetic resonance (FMR) excitation, 8,9 spin-wave excitation 10 and dynamic magnetization switching, [11][12][13][14] have brought great changes to research in this field. Modulations of the Curie temperature, 15 domain wall propagation, 16,17 interfacial Dzyaloshinskii-Moriya interaction 18 and proximity-induced magnetism 19 have also been demonstrated. These results indicate the feasibility of constructing voltage-driven spintronic devices, such as voltage-torque magnetoresistive random access memory devices.…”

Spin wave eigenmodes in transversely magnetized thin film ferromagnetic wires

“…Studies of these effects such as fieldand current-induced domain wall motion [1][2][3][4][5][6][7] , domain wall magneto-resistance [8][9][10] and the interaction of spin waves with nanoscale spin textures such as domain walls, vortices and skyrmions [11][12][13][14][15][16][17] heavily rely on the understanding of transport and magnetization dynamics in ferromagnetic nanowires. More recently, ferromagnetic nanowires proved to be useful for studies of inverse spin Hall effect 19 and spin orbit torques [20][21][22][23] .…”

Ferroelectric control of magnetic domains in ultra-thin cobalt layers

“…In addition, if we assume a nucleation volume of (10 nm) 3 , the MAE change is of the order of 10 4 J/m 3 , which is consistent with the anisotropy changes obtained in the same material for the electric field of 0.1 V/nm. 11 A close examination of the depletion image in Figs. 2(a) and 2(b) reveals some enhancement of switching occurring at the electrode boundaries.…”

“…10 Thus, a weak change of charge density induced by the electric field at the extremely narrow interface-adjacent layer is sufficient for a substantial change of coercivity, 5-7 T C , 8,9 and magnetic domain kinetics. 11,12 In context of these findings, the ferroelectric/ferromagnetic heterostructures become of interest for electronic elements operational within the conventional temperature range. First principles calculations performed for multilayers combining ultra-thin Co layers and P(VDF-TrFE) (polyvinylidene fluoride-trifluoroethylene) ferroelectric copolymer confirm an appreciable multiferroic coupling.…”

“…The other implication of the field-effect-tuned MAE is a possibility to change the domain wall (DW) velocity. [10][11][12] In order to directly observe the impact of the ferroelectric gate polarization on the DW propagation, we study a different area in a thinner part of the Al wedge resulting in a more oxidized Co/AlOx interface and greater MAE. Due to the relatively high MAE, the switching is triggered in a very limited number of reversed domains and develops further through the expansion of these domains (as shown in Movies 3 and 4 in the supplementary material 18 ).…”