arXiv subjects

Mariya Iv. Trukhanova

Publications and source records attributed to Mariya Iv. Trukhanova.

At least 19 recordsLinked to original sources

arXiv2026

Spin-current model of electric polarization with the tensor gyromagnetic ratio

The spin-current model of electric polarization of spin origin is developed for a magnetic structure with anisotropic tensor gyromagnetic ratio (g-factor). Three mechanisms of the magnetoelectric effect are proposed, caused by the symmetric Heisenberg exchange interaction, the Dzyaloshinsky-Moriya interaction, and the spin-spin interaction related to the odd anisotropy of the symmetric exchange interaction of magnetic ions via nonmagnetic ion. The dependence of electric polarization on the spin density and tensor g-factor in the generalized spin-current model is derived. New solutions for macroscopic electric polarization, that arise in the cycloidal and helicoidal spin orders and are caused by the non-diagonal components of the gyromagnetic ratio, are predicted. The extended of the spin-current model to including a tensor g-factor can be important for the magnetic ferroelectrics with heavy ions which take part in the formation of magnetoelectric effect.

cond-mat.other↗

arXiv2026

Dynamic effects of external axion fields in a system of many particles with spin

We develop the theoretical model that describes dynamic non-equilibrium effects of external inertial and axion fields in a system of particles with spin. The possibility of using the spin density and the current density of non-relativistic quantum particle systems for the detection of the hypothetical axion-like dark matter is discussed. The resulting closed system of dynamic equations encompasses the continuity equation, the momentum balance equation, and the spin density evolution equation, accounting for the influence of the spin-rotation coupling and the external axion fields. The new formalism opens up new perspectives for an experimental search of dark matter axions.

hep-th↗

arXiv2025

Mean-field theory of the electromagnon resonance

We present the analytical theory of the electromagnon resonance for the multiferroics of spin origin. We consider the spin density evolution under the influence of magnetoelectric coupling in the presence of the electromagnetic wave. The dielectric permeability is found for the eigen-wave perturbations accompanied by perturbations of the electric field. The imaginary part of the dielectric permeability is found as the function of the applied electric field frequency, while the frequency of the eigen-waves is found from the dispersion equation as the function of the wave vector and parameters of the system. The result shows the existence of two peaks. One sharp peak is associated with the magnon resonance, while the second wide peak at the approximately four times smaller frequency is interpreted as the electromagnon resonance in accordance with existing experimental data.

cond-mat.mtrl-sci↗

arXiv2024

Classical electrodynamics and spin-torsion coupling effects

We study the Poincaré gauge theory of gravity with the most general Lagrangian quadratic in curvature and torsion, focusing on the possible interaction of the axial torsion with the electromagnetic field. From the analysis of the closed system of field equations, we identify the magnetic helicity density and the spin density of the electromagnetic field as the components of the source for the torsion field. We consider the propagation of a linearly polarized plane electromagnetic wave and demonstrate the ``dichroism'' or the polarization rotation effect under the action of external electric and magnetic fields orthogonal to the direction of wave propagation.

gr-qc↗

arXiv2024

Search for manifestations of spin-torsion coupling

We investigate the axial vector torsion-spin coupling effects in the framework of the Poincaré gauge theory of gravity with the general Yang-Mills type Lagrangian. The dynamical equations for the ``electric'' and ``magnetic'' components of the torsion field variable are obtained in the general form and it is shown that the helicity density and the spin density of the electromagnetic field appear as the physical sources. The modified Maxwell's equations for the electromagnetic field are derived, and the electromagnetic wave propagation under the action of the uniform homogeneous torsion field is considered. We demonstrate the Faraday effect of rotation of the polarization for such a wave, and establish the strong bound on the possible cosmic axial torsion field from the astrophysical data.

gr-qc↗

arXiv2024

Electric polarization evolution equation for antiferromagnetic multiferroics with the polarization proportional to the scalar product of the spins

The spin current model of electric polarization of multiferroics is justified via the quantum hydrodynamic method and the mean-field part of the spin-orbit interaction. The spin current model is applied to derive the electric polarization proportional to the scalar product of the spins of the near by ions, which appears to be caused by the Dzylaoshinskii-Moriya interaction. Symmetric tensor spin structure of the polarization is discussed as well. We start our derivations for the ferromagnetic multiferroic materials and present the further generalization for the antiferromagnetic multiferroic materials. We rederive the operator of the electric dipole moment, which provides the macroscopic polarization obtained via the spin current model. Finally, we use the quantum average of the found electric dipole moment operator in order to derive the polarization evolution equation for the antiferromagnetic multiferroic materials. Possibility of spiral spin structures is analyzed.

cond-mat.mtrl-sci↗

arXiv2024

Polarization evolution equation for the exchange-strictionally formed II-type multiferroic materials

The multiferroics are the materials, where single cell of a magnetically order crystal forms an electric dipole moment. We derive equation for the evolution of the macroscopic density of the electric dipole moment (polarization of the system). The derivation is made within the "quantum hydrodynamic" method, which allows to derive equations for the evolution of the macroscopic functions of the quantum systems starting with the microscopic description. In this work we do not consider the microscopic level of individual electrons and ions, but we start our analysis from the combination of ions in cells of the crystal. We present an effective Hamiltonian for the evolution of such intermediate scale objects. We also apply the equation for the electric dipole moment of the single cell, which is recontracted in the corresponding operator. Using this operator and the wave function of combination of ions in the cell, we define the macroscopic density of the electric dipole moment. Finally, we apply the nonstationary Schrodinger equation with the chosen Hamiltonian in order to derive equation evolution of the polarization. The derivation is made for the dipole formed by the exchange-striction mechanism in the II-type multiferroic materials. The interaction caused term in the polarization evolution equation is found to be proportional to the fourth space derivative of mixed product (triple scalar product) of three spin density vectors. Conditions are discussed for the regime, where interaction appears in a smaller order on the space derivatives.

cond-mat.mtrl-sci↗

arXiv2024

A new quantum hydrodynamic description of ferroelectricity in spiral magnets

The strong coupling between magnetism and ferroelectricity was found in rare earth manganites, where the electric polarization could be induced by special magnetic ordering. There is no theoretical model that would allow us to study the static and dynamic properties of electric polarization in strongly correlated magnetic dielectrics. In the presented research, we have taken the main step towards the construction of such a fundamental model, and made a direct connection between the microscopic Katsura-Nagaosa-Balatsky theory and Mostovoy's phenomenological model for magnetically induced polarization. A novel description of the ferroelectricity of spin origin is proposed within the framework of the many-particle quantum hydrodynamics method. It is applied to the study of cells of magnetic ions, where the electric dipole moment is proportional to the vector product of spins. Our approach is based on the many-particle Pauli equation, where the influence of an external magnetic field is considered. We define the electric dipole moment operator of the ion cell and introduce the macroscopic polarization as the quantum mechanical average of that operator. We formulate a model for the description of nonequilibrium polarization and derive a new polarization evolution equation. The polarization switching in ferroelectric magnets with the spiral spin-density-wave state is considered, and we demonstrate that the proposed model yields known results and can predict novel effects. The dynamic magnetoelectric effect can be investigated by employing this novel equation to study the evolution of polarization.

cond-mat.mtrl-sci↗

arXiv2024

A new microscopic representation of the spin dynamics in quantum systems with the Coulomb exchange interactions

There is a version of the Landau-Lifshitz equation that takes into account the Coulomb exchange interactions between atoms, expressed by the term $\sim\bm{s}\times\triangle\bm{s}$. On the other hand, ions in the magnetic materials have several valence electrons on the $d$-shell, and therefore the Hamiltonian of many-electron atoms with spins $S>1$ should include a biquadratic exchange interaction. We first propose a new fundamental microscopic derivation of the spin density evolution equation with an explicit form of biquadratic exchange interaction using the method of many-particle quantum hydrodynamics. The equation for the evolution of the spin density is obtained from the many-particle Schrodinger-Pauli equation and contains the contributions of the usual Coulomb exchange interaction and the biquadratic exchange. Furthermore, the derived biquadratic exchange torque in the spin density evolution equation is proportional to the nematic tensor for the medium of atoms with spin $\textit{S = 1}$. Our method may be very attractive for further studies of the magnetoelectric effect in multiferroics.

cond-mat.mtrl-sci↗

arXiv2021

Quantum hydrodynamics of spinning particles in electromagnetic and torsion fields

We develop a many-particle quantum-hydrodynamical model of fermion matter interacting with the external classical electromagnetic and gravitational/inertial and torsion fields. The consistent hydrodynamical formulation is constructed for the many-particle quantum system of Dirac fermions on the basis of the nonrelativistic Pauli-like equation obtained via the Foldy-Wouthuysen transformation. With the help of the Madelung decomposition approach, the explicit relations between the microscopic and macroscopic fluid variables are derived. The closed system of equations of quantum hydrodynamics encompasses the continuity equation, and the dynamical equations of the momentum balance and the spin density evolution. The possible experimental manifestations of the torsion in the dynamics of spin waves is discussed.

hep-th↗

arXiv2021

Hydrodynamic description of Weyl fermions in condensed state of matter

Due to the many unique transport properties of Weyl semimetals, they are promising materials for modern electronics. We investigate the electrons in the strong coupling approximation near Weyl points based on their representation as massless Weyl fermions. We have constructed a new fluid model based on the many-particle quantum hydrodynamics method to describe the behavior of electrons gas with different chirality near Weyl points in the low-energy limit in the external electromagnetic fields, based on the many-particle Weyl equation and many-particle wave function. The derived system of equations forms a closed apparatus for describing the dynamics of the electron current, spin density and spin current density. Based on the proposed model, we considered small perturbations in the Weyl fermion system in an external uniform magnetic field and predicted the new type of eigenwaves in the systems of the electrons near the Weyl points.

cond-mat.mes-hall↗

arXiv2021

Quantum hydrodynamics of the spinor Bose-Einstein condensate at non-zero temperatures

Finite temperature hydrodynamic model is derived for the spin-1 ultracold bosons by the many-particle quantum hydrodynamic method. It is presented as the two fluid model of the BEC and normal fluid. The linear and quadratic Zeeman effects are included. Scalar and spin-spin like short-range interactions are considered in the first order by the interaction radius. It is also represented as the set of two nonlinear Pauli equations. The spectrum of the bulk collective excitations is considered for the ferromagnetic phase in the small temperature limit. The spin wave is not affected by the presence of the small temperature in the described minimal coupling model, where the thermal part of the spin-current of the normal fluid is neglected. The two sound waves are affected by the spin evolution in the same way as the change of spectrum of the single sound wave in BEC, where speed of sound is proportional to $g_{1}+g_{2}$ with $g_{i}$ are the interaction constants.

cond-mat.quant-gas↗

arXiv2021

Many-particle Quantum Hydrodynamics of Spin-1 Bose-Einstein Condensates

We develop a novel model of the magnetized spin-1 Bose-Einstein condensate (BEC) of neutral atoms, using the method of many-particle quantum hydrodynamic (QHD) and propose an original derivation of the system of continual equations. We consider bosons with a spin-spin interaction and a short range interaction in the first order in the interaction radius, on the of basis of the self-consistent field approximation of the QHD equations. We demonstrate that the dynamics of the fluid velocity and magnetization is determined by a nontrivial modification of the Euler and Landau-Lifshitz equation, and show that a nontrivial modification of the spin density evolution equation contains the spin torque effect that arises from the self-interactions between spins of the bosons. The properties of the dispersion spectrum of collective excitations are described. We obtain the new contribution of the self-interaction of spins in the spin wave spectrum together with the influence of an external magnetic field and spin-spin interactions between polarized particles. The anisotropic spin wave instability is predicted.

cond-mat.quant-gas↗

arXiv2020

Geometrical interpretation of the wave-pilot theory and manifestation of the spinor fields

Using the hydrodynamical formalism of quantum mechanics for a Schrodinger spinning particle, developed by T. Takabayashi, J. P. Vigier and followers, that involves vortical flows, we propose the new geometrical interpretation of the wave-pilot theory. The spinor wave in this interpretation represents an objectively real field and the evolution of a material particle controlled by the wave is a manifestation of the geometry of space. We assume this field to have a geometrical nature, basing on the idea that the intrinsic angular momentum, the spin, modifies the geometry of the space, which becomes a manifold, that is represented as a vector bundle with a base formed by the translational coordinates and time, and the fiber of the bundle, specified at each point by the field of an tetrad $e^a_μ$, forms from the bilinear combinations of spinor wave function. It was shown, that the spin vector rotates following the geodesic of the space with torsion and the particle moves according to the geometrized guidance equation. This fact explains the self-action of the spinning particle. We show that the curvature and torsion of the spin vector line is determined by the space torsion of the absolute parallelism geometry.

quant-ph↗

arXiv2020

Bosonic bright soliton in the mixture of repulsive Bose-Einstein condensate and polarized ultracold fermions under influence of the pressure evolution

Repulsive Bose-Einstein condensate, where the short-range interaction is included up to the third order by the interaction radius, demonstrates existence of a bright soliton in a narrow interval of parameters. This soliton is studied here for the boson-fermion mixture, where spin-1/2 fermions are consider in the regime of full spin polarization. Influence of fermions via the boson-fermion interaction is considered up to the third order by the interaction radius. Fermions themselves are considered by hydrodynamic model including the pressure evolution equation. Interaction between fermions is considered. The first order by the interaction radius gives zero contribution in the Euler equation and the pressure evolution equation, but the third order by the interaction radius provides nonzero contributions in both equations. Repulsive (attractive) boson-fermion interaction leads to the bright (dark) fermionic soliton.

cond-mat.quant-gas↗

arXiv2019

Dipolar-drift and collective instabilities of skyrmions in crossed nonuniform electric and magnetic fields in a chiral magnetic insulator

Skyrmions dynamics in the approximation of point-particle skyrmions is considered in the multiferroic insulators, where the spiral magnetic structure is accompanied by finite electric dipole moment. The skyrmion motion is studied in the gradients of perpendicular magnetic and electric fields. The nonuniform magnetic field with a fixed gradient magnitude leads to the spiral motion, where skyrmion circulates in the plane perpendicular to the direction of magnetic field. The frequency of circulation is fixed by the derivative of the external magnetic field and the magnitude of the dipole moment. Application of additional electric field which perpendicular to the magnetic field, but their gradients have same direction leads to the drift motion of skyrmions resulting in the magneto-dipolar Hall effect. Hydrodynamics of the gas of interacting skyrmions in crossed nonuniform electric and magnetic fields shows the new type of hydrodynamical instability caused by the drift motion. Three regimes of instability are described.

cond-mat.mes-hall↗

arXiv2018

The geometro-hydrodynamical formalism of quantum spinning particle

We present the development of the realistic geometro-hydrodynamical formalism of quantum mechanics for the spinning particle, that involves the vortical flows and is based on the idea, that the spinor wave represents a new type of physical field, propagating in space-time and influencing the corpuscule embedded in the wave. We assume that this new field created by the intrinsic spin of the particle and can produce new intrinsic forces and torques affecting the particle with spin. We derive and discuss physical effects of this field.

gr-qc↗

arXiv2017

The Geometro-Hydrodynamical Representation of the Torsion Field

We construct the geometro-hydrodynamical formalism for a spinning particle based on the six-dimensional manifold of autoparallelism geometry which is represented as a vector bundle with a base formed by the manifold of the translational coordinates and a fibre specified at each point by the field of an orthogonal coordinate frame underlying the classical spin. We show that the geometry of oriented points leads to the existence of torsion field with the source - the classical spin. We expand the geometro-hydrodynamical representation of Pauli field developed by Takabayasi and Vigier. We show that the external torsion field has a force effect on the velocity and spin fields via the spin-vorticity, which is characteristic of the space structure with the inhomogene triad field. The possible experimental effects of torsion field are discussed.

gr-qc↗