Related papers: Order parameter fluctuation effects on current-ind…
The magnetoelectric effect has been actively studied in multiferroics since the first observation in an antiferromagnetic, $\mathrm{Cr_2O_3}$. This effect appears in systems without spatial inversion symmetry and time-reversal symmetry and…
We consider a theory for a two-dimensional interacting conduction electron system with strong spin-orbit coupling on the interface between a topological insulator and the magnetic (ferromagnetic or antiferromagnetic) layer. For the…
The polarization of a material and its response to applied electric and magnetic fields are key solid-state properties with a long history in insulators, although a satisfactory theory required new concepts such as Berry-phase gauge fields.…
We investigate the interplay of quantum fluctuations and magnetic anisotropies in metallic ferromagnets. Our central result is that fluctuations close to a quantum critical point can drive the moments to point along a magnetic hard axis. As…
A conventional and rotating magnetoelectric effect of a half-filled spin-electron model on a doubly decorated square lattice is investigated by exact calculations. An importance of the electron hopping and spatial orientation of the…
We study ordering mechanisms which are induced by the quantum fluctuation in fully frustrated Ising spin systems. Since there are many degenerated states in frustrated systems, "order by thermal disorder" often takes place due to a kind of…
We investigated the series of temperature and field-driven transitions in LuFe$_2$O$_4$ by optical and M\"{o}ssbauer spectroscopies, magnetization, and x-ray scattering in order to understand the interplay between charge, structure, and…
Spin-polarized current effect is studied on the static and dynamic magnetization of the antiferromagnet in a ferromagnet - antiferromagnet nanojunction. The macrospin approximation is generalized to antiferromagnets. Canted…
We describe an ab initio theory of finite temperature magnetism in strongly-correlated electron systems. The formalism is based on spin density functional theory, with a self-interaction corrected local spin density approximation…
In frustrated magnets the Dzyaloshinsky-Moriya interaction arising from spin-orbit coupling can induce a magnetic long-range order. Here, we report a theoretical prediction of thermal Hall effect in frustrated kagom\'e magnets such as…
We study the effect of quenched disorder on the ordering of orbital and magnetic degrees of freedom in a two-dimensional, two-band double-exchange model for $e_g$ electrons coupled to Jahn-Teller distortions. Using a real-space Monte Carlo…
The theory of orbital magnetism in disordered metals is reviewed, and extended to include a broad range of temperatures and fields. Sample-to-sample fluctuations in the orbital magnetic susceptibility are studied. In a given sample these…
The current theoretical and experimental situations are reviewed for low-dimensional insulating systems with a low magnetic transition temperature TM and pronounced short-range magnetic order above this temperature. Both the standard and…
Exchange interaction tends to favor collinear or coplanar magnetic orders in rotationally invariant spin systems. Indeed, such magnetic structures are usually selected by thermal or quantum fluctuations in highly frustrated magnets. Here we…
In itinerant magnetic systems with disorder, the quantum Griffiths phase at T=0 is unstable to formation of a cluster glass (CG) of frozen droplet degrees of freedom. In the absence of the fluctuations associated with these degrees of…
We study f-electron lattice models which are capable of supporting octupolar, as well dipolar and quadrupolar, order. Analyzing the properties of the Gamma8 ground state quartet, we find that (111)-type combinations of the Gamma5 octupoles…
The influence of dilution with non--magnetic impurities on the order in the ground state of the $S=1/2$ Heisenberg antiferromagnet is investigated by Quantum Monte Carlo simulations. Data of the spin correlation functions and thermodynamic…
Ferroelectric and ferromagnetic materials possess spontaneous electric and magnetic order, respectively, which can be switched by the corresponding applied electric and magnetic fields. Multiferroics combine these properties in a single…
The loop-current state discovered in the pseudogap phase of cuprates breaks time reversal symmetry and lowers the point group symmetry of the crystal. The order parameter and the magnetic structure within each unit cell which is associated…
Using the determinant quantum Monte Carlo method, we study the magnetic susceptibility in the parameter space of the on-site interaction $U$, temperature $T$, electron filling $\avg{n}$, and the frustration control parameter $t^{\prime}$…