Robust Formation of Skyrmions and Topological Hall Effect Anomaly in Epitaxial Thin Films of MnSi

Abstract

Magnetotransport properties have been investigated for epitaxial thin films of B20-type MnSi grown on Si(111) substrates. Lorentz transmission electron microscopy images clearly point to the robust formation of Skyrmions over a wide temperature-magnetic field region. New features distinct from those reported previously for MnSi are observed for epitaxial films: a shorter (nearly half) period of the spin helix and Skyrmions, and a topological Hall effect anomaly consisting in ∼2.2 times enhancement of the amplitude and in the opposite sign with respect to bulk samples.

A Centrosymmetric Hexagonal Magnet with Superstable Biskyrmion Magnetic Nanodomains in a Wide Temperature Range of 100–340 K

“…including Refs. [1][2][3][4][5][6][7][8][9][10][11][12], [22], [29][30][31], [33]. The red solid squares indicate the experimental data based on the in-situ Lorentz TEM observations.…”

“…In Figure 4a, we show the Hall resistivities, xy  , measured at various temperatures from 340 K to 10 K. In the presence of a topological spin texture, the Figure 4c, the perpendicular magnetoresistance is very small (less than 3%) and S R is nearly constant with a magnetic field. Therefore, as in previous studies [29] , S R can simply be determined from function of the applied magnetic field is evident, which was assumed to be a unique signature of THE [2,28,30] . The T xy  values obtained from the experimental data measured over the temperature range of 10 K to 350 K are shown in Figure 4b, where a sizable T xy  is clearly found over the whole temperature range.…”

“…the skyrmion spin textures in helimagnets with B20 cyrstal structure [2,[27][28][29][30] . In Figure 4a, we show the Hall resistivities, xy  , measured at various temperatures from 340 K to 10 K. In the presence of a topological spin texture, the Figure 4c, the perpendicular magnetoresistance is very small (less than 3%) and S R is nearly constant with a magnetic field.…”

Magnetization Relaxation and Geometric Forces in a Bose Ferromagnet

“…Furthermore, spin textures with nonzero chirality, such as the skyrmion lattice observed recently [13,14] induce the so-called topological Hall effect [5,6]. In addition, the coupling between magnetization and quasiparticles has also been shown to give rise to novel forms of magnetization relaxation in this case.…”

“…In particular after the advent of the Berry phase [3], a large number of manifestations of geometric forces, including the optical Magnus effect [4], the topological Hall effect [5,6] and geometric forces due to synthetic gauge fields [7] have been predicted and observed.…”