Related papers: Multicomponent Skyrmion lattices and their excitat…
In cubic noncentrosymmetric ferromagnets uniaxial distortions suppress the helical states and stabilize Skyrmion lattices in a broad range of thermodynamical parameters. Using a phenomenological theory for modulated and localized states in…
We report the discovery of a thermodynamically stable skyrmion-antiskyrmion lattice in two-dimensional heterostructures, a novel state exhibiting a net-zero global topological charge owing to an equal population of skyrmions and…
Spin textures arise in the effective action approach to the quantum Hall effect. Up to now these textures, also called Skyrmions, have been mainly studied using approximations. Studies of its finite density form, the crystal, have been…
Excitation with a massive spin reversal of the individual skyrmion/antiskyrmion type is theoretically studied in a quantum Hall ferromagnet, where the zero and first Landau levels are completely occupied only by electrons with spins aligned…
A number of strongly correlated heavy fermion compounds, such as samarium (Sm), ytterbium (Yb), plutonium (Pu) hexaboride, are predicted to become topological insulators at low temperatures. These systems support massless Dirac fermions…
We analyze bilayer quantum Hall ferromagnets, whose underlying symmetry group is SU(4). Spin-pseudospin coherence develops spontaneously when the total electron density is low enough. Quasiparticles are CP^3 skyrmions. One skyrmion induces…
Density functional theory calculations with an on-site Coulomb repulsion term (GGA+U method) reveal competing ground states in (111) oriented (LaAlO$_3$)$_M$/(SrTiO$_3$)$_N$ superlattices with n-type interfaces, ranging from spin, orbital…
We report measurements of the interaction-induced quantum Hall effect in a spin-polarized AlAs two-dimensional electron system where the electrons occupy two in-plane conduction band valleys. Via the application of in-plane strain, we tune…
We report the emergence of a square-shaped skyrmion lattice in multi-orbital $f$-electron systems with easy-axis magnetic anisotropy on a centrosymmetric square lattice. By performing mean-field calculations for an effective localized model…
The ground states of square lattice two-dimensional antiferromagnets with anisotropy in an external magnetic field are determined using Monte Carlo simulations and compared to theoretical analysis. We find a new phase in between the…
We investigate the instability toward a skyrmion crystal under an in-plane magnetic field in centrosymmetric tetragonal magnets. By performing the simulated annealing for a spin model on the square lattice, we find that the interplay among…
Motivated by recent experiments in Gd$_3$Ru$_4$Al$_{12}$, we demonstrate the emergence of atomic scale Skyrmions in interacting spins on a breathing kagome lattice with competing nearest neighbor ferromagnetic and next nearest neighbor…
We apply the theory of elasticity to study the effects of skyrmion mass on lattice dynamics in quantum Hall systems. We find that massive Skyrme lattices behave like a Wigner crystal in the presence of a uniform perpendicular magnetic…
Nematic systems are two component superconductors that break rotational symmetry, but exhibit a mixed symmetry that couples spatial rotations and phase difference rotations. We show that a consequence of this induced spatial anisotropy is…
We study the effect of symmetry breaking perturbations in the one-dimensional SU(4) spin-orbital model. We allow the exchange in spin ($J_1$) and orbital ($J_2$) channel to be different and thus reduce the symmetry to SU(2) $\otimes$ SU(2).…
We use the Hamiltonian theory developed by Shankar and Murthy to study a quantum Hall system in a tilted magnetic field. With a finite width of the system in the $z$ direction, the parallel component of the magnetic field introduces…
We report tilted-field magnetotransport measurements of two-dimensional electron systems in a 200 Angstrom-wide Al(0.13)Ga(0.87)As quantum well. We extract the energy gap for the quantum Hall state at Landau level filling \nu =1 as a…
The Coulomb exchange interaction is the driving force for quantum coherence in quantum Hall systems. We construct a microscopic Landau-site Hamiltonian for the exchange interaction in bilayer quantum Hall ferromagnets, which is…
Quasiparticle excitations in material solids often experience a fictitious gauge field, which can be a potential source of intriguing transport phenomena. Here, we show that low-energy excitations in insulating antiferromagnetic skyrmion…
In condensed matter physics, the study of electronic states with SU(N) symmetry has attracted considerable and growing attention in recent years, as systems with such a symmetry can often have a spontaneous symmetry-breaking effect giving…