Related papers: Dissipation processes in the insulating skyrmion c…
The spinel compounds MnSc_2X_4 are highly frustrated and candidate materials for vortex-like 3q magnetic states, such as skyrmions, with propagation vectors in the [111] plane. Because of the strong magnetoelastic coupling, we could extract…
We report small angle neutron scattering (SANS) measurements of the skyrmion lattice in (Cu$_{0.976}$Zn$_{0.024}$)$_2$OSeO$_3$ under the application of an electric field. These measurements show an expansion of the skyrmion lattice…
LiCu$_3$O$_3$ is a novel 2D S=1/2 antiferromagnet with randomly depleted square lattice. The crystal structure contains two types of square planes with different Cu$^{2+}\rightarrow$ Li$^{+}$ substitution rates (20% and 40%). $^7$Li NMR and…
I revisit the well-known phase transition between the hexagonal skyrmion lattice and the homogeneous state within the phenomenological Dzyaloshinskii theory for chiral magnets which includes only the exchange, Dzyaloshinskii-Moriya and…
We study possible paramagnetic phases of antiferromagnets on the Shastry-Sutherland lattice by a gauge-theoretic analysis of fluctuations in a theory with Sp(2N) symmetry. In addition to the familiar dimer phase, we find a confining phase…
We have used inelastic neutron scattering to measure the magnetic excitation spectrum along the high-symmetry directions of the first Brillouin zone of the magnetic skyrmion hosting compound Cu$_2$OSeO$_3$. The majority of our scattering…
Co$_3$Sn$_2$S$_2$, a Weyl semimetal that consists of layers of Kagome lattices, transitions from a high-temperature paramagnetic phase to a low-temperature ferromagnetic phase below 177 K. The phase transition occurs through an intermediate…
The breathing mode of a skyrmion, corresponding to coupled oscillations of its size and chirality angle is studied numerically for a conservative classical-spin system on a $500\times500$ lattice. The dependence of the oscillation frequency…
A caged compound CeOs2Al10, crystallizing in the orthorhombic YbFe2Al10-type structure, undergoes a mysterious phase transition at T_0=29 K. We report the results of electron diffraction, magnetization, and magnetoresistance for single…
The depth dependence of the crystallographic parameters mosaicity, lattice parameter variation and integrated reflectivity and of the critical scattering above the 105 K structural phase transition of SrTiO$_3$ have been studied in five…
Chiral magnets, such as MnSi, display a rich finite temperature phase diagram in an applied magnetic field. The most unusual of the phases encountered is the so called A-phase characterized by a triangular lattice of skyrmion tubes. Its…
Controlled movement of nano-scale stable magnetic objects has been proposed as the foundation for a new generation of magnetic storage devices. Magnetic skyrmions, vortex-like spin textures stabilized by their topology are particularly…
Dielectric properties were investigated under various magnitudes and directions of magnetic field (H) for a chiral magnetic insulator Cu2OSeO3. We found that the skyrmion crystal induces electric polarization (P) along either in-plane or…
We have investigated the effects of structure change and electron correlation on SrTiO$_{3}$ single crystals using angle-resolved photoemission spectroscopy. We show that the cubic to tetragonal phase transition at 105$^\circ$K is…
We report on the linear optical properties of the chiral magnet Cu2OSeO3, specifically associated with the absence of inversion symmetry, the chiral crystallographic structure, and magnetic order. Through spectroscopic ellipsometry, we…
Skyrmions are nanometric spin whirls that can be stabilized in magnets lacking inversion symmetry. The properties of isolated skyrmions embedded in a ferromagnetic background have been intensively studied. We show that single skyrmions and…
We propose quantum phase transitions beyond the Landau's paradigm of Sp(4) spin Heisenberg models on the triangular and square lattices, motivated by the exact Sp(4)$\simeq$ SO(5) symmetry of spin-3/2 fermionic cold atomic system with only…
The electronic properties of excitonic insulators have been examined precisely in recent years. Pictures of exciton condensation may be applied to the spin-state transition observed in perovskite cobalt oxides. We examine the crystal-field…
I consider skyrmionic states in non-centrosymmetric magnets near the ordering temperatures. I show that the interaction between the chiral skyrmions, being repulsive in a broad temperature range, changes into attraction at high…
The skyrmion is a topologically stable spin texture, in which the spin direction wraps a sphere. The topological nature gives rise to emergent electromagnetic phenomena such as topological Hall effect. Recently, the crystallization of…