Related papers: Quantum field theory of topological spin dynamics
Topological states of matter are, generally, quantum liquids of conserved topological defects. We establish this by constructing and analyzing topological field theories which describe the dynamics of field singularities using gauge fields.…
Two hundred years ago, Andr\'e-Marie Amp\`ere discovered that electric loops in which currents of electrons are generated by a penetrating magnetic field can interact with each other. Here we show that Amp\`ere's observation can be…
Magnetic anisotropies often originate from the spin-orbit coupling and determine magnetic ordering patterns. We develop a microscopic theory for DC electric-field controls of magnetic anisotropies in magnetic Mott insulators and discuss its…
We develop a multiscale approach to magnetoelectric effects, bridging atomistic and continuum models, with all parameters determined from ab initio electronic structure calculations. We show that the parameters of the model are equivalent…
We recently showed that spin fluctuations of noncoplanar magnetic states can induce topological superconductivity in an adjacent normal metal [M{\ae}land et al., Phys. Rev. Lett. 130, 156002 (2023)]. The noncolinear nature of the spins was…
In itinerant magnets, the indirect exchange coupling of Ruderman-Kittel-Kasuya-Yosida type is known to stabilize incommensurate spin spiral. Whereas an account of higher order spin interactions favors the formation of a noncoplanar magnetic…
We develop a comprehensive theory of twisted bilayer magnetism. Starting from the first-principles calculations of two-dimensional honeycomb magnet CrI3, we construct the generic spin models that represent a broad class of twisted bilayer…
Here, we reveal our recent progress on a geometrical approach of quantum physics and topological crystals linking with Dirac magnetic monopoles and gauge fields through classical electrodynamics. The Bloch sphere of a quantum spin-1/2…
It is shown here that a Kagom\'e magnet, with Heisenberg and Dzyaloshinskii-Moriya interactions causes non trivial topological and chiral magnetic properties. Chirality---that is, left or right handedness---is a very important concept in a…
We present topological features of the magnetic response (orbital and spin) of a two-dimensional degenerate and non interacting electron gas due to inhomogeneous applied magnetic fields. These issues are analysed from the point of view of…
The noncollinear spin textures provide promising avenues to stabilize exotic magnetic phases and excitations. They have attracted vast attention owning to their nontrivial band topology in the past decades. Distinct from the conventional…
We focus on quantum systems that can be effectively described as a localized spin-$s$ particle subject to a static magnetic field coplanar to a coexisting elliptically rotating time-periodic field. Depending on the values taken on by the…
Atomistic spin models are of great value for predicting and understanding the magnetic properties of real materials, and extensions of the existing models open routes to new physics and potential applications. The Dzyaloshinskii-Moriya…
Chiral magnets give rise to the anti-symmetric Dzyaloshinskii-Moriya (DM) interaction, which induces topological nontrivial textures such as magnetic skyrmions. The topology is characterized by integer values of the topological charge. In…
Atomistic spin models have found enormous success in addressing the properties of magnetic materials, grounded on the identification of the relevant underlying magnetic interactions. The huge development in the field of magnetic skyrmions…
One-dimensional quantum rings with Rashba and Dresselhaus spin-orbit couplings are studied analytically and are in perfect agreement with the numerical results. The topological charge of the spin field defined by the winding number along…
Magnetoelectric properties are studied by a combined experimental and theoretical study of a quasi-two-dimensional material composed of square cupolas, Ba(TiO)Cu$_4$(PO$_4$)$_4$. The magnetization is measured up to above the saturation…
We show that the classical non-abelian pure Chern-Simons action is related to nonrelativistic models in (2+1)-dimensions, via reductions of the gauge connection in Hermitian symmetric spaces. In such models the matter fields are coupled to…
By considering specific limits in the gauge coupling constant of pure Yang--Mills dynamics, it is shown how there exist topological quantum field theory sectors in such systems defining nonperturbative topological configurations of the…
Motivated by recent experiments on the observation of room temperature skyrmions in a layered heterostructure and subsequent demonstration of topological Hall effect in the same system, we have studied a minimal model of itinerant electrons…