Vital role of magnetocrystalline anisotropy in cubic chiral skyrmion hosts

Abstract

Magnetic anisotropy is anticipated to govern the formation of exotic spin textures reported recently in cubic chiral magnets, like low-temperature tilted conical and skyrmion lattice (SkL) states and metastable SkLs with various lattice geometry. Motivated by these findings, we quantified the cubic anisotropy in a series of CoZnMn-type cubic chiral magnets. We found that the strength of anisotropy is highly enhanced towards low temperatures. Moreover, not only the magnitude but also the character of cubic anisotropy drastically varies upon changing the Co/Mn ratio. We correlate these changes with temperature- and composition-induced variations of the helical modulation vectors, deformations of skyrmions, structural rearrangements of the metastable SkLs and the large enhancement of Gilbert damping. Similar studies on magnetic anisotropy are required for the quantitative, unified description of the known stable and metastable modulated spin textures and for the systematic exploration of novel ones in this large class of skyrmion hosts.

Dynamic transition of current-driven single-skyrmion motion in a room-temperature chiral-lattice magnet

“…The drift velocity of a skyrmion is given by where is the velocity of the conduction electrons. The parameters are given as follows 6 , 30 : dissipative force 5.577 , damping factor 0.05, nonadiabatic coefficient 0.03, pinning term with the pinning velocity = 3.2, lattice constant a = 6.32 , local magnetic moment M = 1, and spin polarization p = 0.1 which was estimated from the ratio of magnetizations in the skyrmion phase to the saturated magnetization at 2 K 24 , 30 .…”

Doping Control of Magnetic Anisotropy for Stable Antiskyrmion Formation in Schreibersite (Fe,Ni)3P with S4 symmetry

“…2022, 34, 2108770 The angle θ is measured from the [001] axis as indicated in the inset, which depicts the single crystal under investigation prepared as a thin cylindrical disk. The solid black line shows a fit by uniaxial magnetocrystalline anisotropy, [37][38][39] as described in the text.…”

Manipulation of Skyrmion Motion Dynamics for Logical Device Application Mediated by Inhomogeneous Magnetic Anisotropy

“…It is well known that the skyrmion structure usually arises as a result of energy competition among the exchange energy, Dzyaloshinskii-Moriya interaction (DMI), demagnetization energy, magnetic anisotropy and Zeeman energy [8]. Previous studies demonstrated that various types of anisotropy terms (e.g., perpendicular magnetic anisotropy (PMA), easy-plane magnetocrystalline anisotropy and cubic anisotropy) may play a prominent role in modulating the skyrmion structures and enhancing their stability [17][18][19][20][21][22][23][24][25]. For instance, PMA can help create and stabilize skyrmions, regulate their structures [13,17,18,26,27], and even enables the stabilization of skyrmion at zero magnetic field in confined nanostructures [8].…”