arXiv subjects

Vladimir A. Zyuzin

Publications and source records attributed to Vladimir A. Zyuzin.

At least 19 recordsLinked to original sources

arXiv2026

Surface weak ferromagnetism

This paper proposes a model of a Néel-ordered antiferromagnet exhibiting a weak ferromagnetic moment restricted to the crystal surface, generated by spin-orbit coupling induced by broken surface symmetries. Depending on crystal termination, the surface magnetic moment can align with identical or opposing signs on the top and bottom surfaces, resulting in a zero Faraday effect paired with a finite Kerr effect upon reflection for the latter configuration.

cond-mat.mes-hall↗

arXiv2026

Magnon equilibrium spin current in collinear antiferromagnets

We theoretically predict that the Dzyaloshinskii-Moriya interaction can induce a magnon equilibrium spin current in collinear antiferromagnets. Such a current, being a response to the effective magnon vector potential, can be considered the magnon analog of the supercurrent in superconductors. The large amplitude of the predicted effect may compensate for the smallness of the Dzyaloshinskii-Moriya interaction, making the equilibrium spin currents experimentally observable. We suggest that an external electric field can play the role of an effective flux that magnons interact with, and we propose an experiment based on the interference of magnons in a ring geometry to verify the concept.

cond-mat.mes-hall↗

arXiv2026

Heavy fermion $\textit{d-f}$ hybrid and the SmB$_6$ low temperature phase

In this Letter we theoretically study physical properties of a model of heavy fermion $d-f$ hybrid. In the studied model two species of fermions have dispersions with different masses, one being much heavier than the other. Hybridization between the fermions at the crossing point of their dispersions doesn't open a true insulating gap leaving a heavy fermion $d-f$ hybrid at the Fermi level. As a result, our theoretical model qualitatively explains experiments on the low-temperature phase of the SmB$_6$. These are the linear in temperature specific heat, saturation of the resistance, and frequency dependence of the optical conductivity. Calculated optical conductivity shows a broadened peak at the twice the value of hybridization as well as a low-frequency tail.

cond-mat.str-el↗

arXiv2026

Magnon thermal Hall effect in collinear antiferromagnets

In this paper we theoretically discuss thermal Hall effect of magnons in insulating Néel ordered antiferromagnets at zero external magnetic field. We show that for compensated Néel order the non-zero thermal Hall effect will occur in the absence of any symmetry between the two magnetic sublattices, thus making the system ferrimagnetic. We then show that collinear Dzyaloshinskii's weak ferromagnets, in which there is a symmetry connecting the magnetic sublattices, also show magnon thermal Hall effect. The thermal Hall effect of magnons will be non-zero by a virtue of the spin-momentum splitting of the magnon spectrum due to the Dzyaloshinskii-Moriya interaction as well as second-nearest exchange interaction different in the two magnetic sublattices, both corresponding to the broken symmetries that lead to the Dzyaloshinskii's invariant. We construct a theoretical model in which an external electric field may change the symmetry of the antiferromagnetic system thus altering the thermal Hall effect of magnons.

cond-mat.mes-hall↗

arXiv2026

Ferromagnet with a noncollinear antiferromagnetic order and anomalous Hall effect

In this paper we introduce a theoretical model of a metallic magnetic system with noncollinear antiferromagnetic order. We introduce a mechanism of indirect interaction of conducting fermions with localized spins based on the tunneling processes of conducting fermions through the localized spins. We demonstrate that interaction of conducting fermions with noncollinear antiferromagnetic order results in odd in momentum spin-momentum locking. The interaction resembles Rashba spin-orbit coupling but breaks the time-reversal symmetry. As a result, we show that a ferromagnet with the noncollinear antiferromagnetic order is an insulator with anomalous Hall effect occurring without any spin-orbit coupling.

cond-mat.mes-hall↗

arXiv2026

Anomalous Hall effect in metallic collinear antiferromagnets

We propose and theoretically study minimal models of Néel ordered collinear (compensated) antiferromagnets that show the anomalous Hall effect. For simplicity, we first consider two-dimensional models of antiferromagnets with two magnetic sublattices on a square lattice. We provide explicit examples of a Néel ordered ferrimagnet and a Dzyaloshinskii weak ferromagnet. Then antiferromagnet on the rutile lattice, that belongs to the class of weak ferromagnets, is studied. We analyze Dzyaloshinskii's invariants for the existence of spontaneous magnetization in these Néel ordered systems. Microscopic calculations of the Berry curvature for the studied systems confirm the validity of these Dzyaloshinskii's invariants. It is shown that the anomalous Hall effect mechanism in these antiferromagnets arises either from the interplay of momentum-dependent exchange interaction of conducting fermions with the Néel order and the spin-orbit coupling. These physical processes originate from the broken symmetries that permit the Dzyaloshinskii's invariant in the system.

cond-mat.mes-hall↗

arXiv2025

Metallic collinear antiferromagnets with mirror-symmetric and asymmetric spin-splittings

In this paper we theoretically describe a distinct class of two-dimensional Néel ordered metallic antiferromagnets on a honeycomb-like lattice in which the two sublattices are connected only by a combination of time-reversal and mirror symmetry operations. As a result of this symmetry, conducting fermions have antiferromagnetic spin-splitting consistent with the symmetry, the mirror-symmetric spin-splitting. It is shown that the anomalous spin Hall effect is expected in such systems. We also consider a system in which there are no symmetries between the sublattices and obtain asymmetric spin-splitting. Such systems are expected to have the anomalous Hall effect.

cond-mat.mes-hall↗

arXiv2024

Anomalous Hall effect in metallic collinear antiferromagnets with charge-density wave order

In this paper we propose two theoretical models of a metallic Néel ordered antiferromagnet with charge-density wave order which shows the anomalous Hall effect. In our models a combination of the Néel order and the charge-density wave order results in spin splitting of the conducting fermions. In addition, spin-orbit coupling is required to drive the anomalous Hall effect. In the first model we analyzed the effects of the Rashba spin-orbit coupling, and of the intrinsic $d-$wave spin-orbit coupling in the second model.

cond-mat.mes-hall↗

arXiv2024

De Haas-van Alphen effect and a giant temperature peak in heavy fermion SmB$_6$ compound

In this paper we suggest a possible explanation of the giant temperature peak in the amplitude of the de Haas-van Alphen oscillations observed at very low temperatures in insulating SmB$_6$ system. Our theoretical model consists of two fermions with particle-like dispersion but with different masses, one much heavier than the other, which hybridize with each other to open up a gap at their degeneracy point. As a result of the hybridization a heavy-fermion hybrid appears at the Fermi level. Our results strongly suggest that it is exactly this heavy-fermion hybrid which results in the giant temperature peak. In addition we propose a scenario when this hybrid has edge states.

cond-mat.str-el↗

arXiv2024

De Haas-van Alphen effect and quantum oscillations as a function of temperature in correlated insulators

We theoretically study a model of excitonic insulators which show de Haas-van Alphen oscillations as well as periodic dependence of the magnetization on inverse temperature. The insulating behavior is due to the Coulomb interaction driven hybridization of fermions at the crossing point of their energy bands. We study this hybridization self-consistently and recover known results by A. Allocca and N. Cooper, SciPost Phys. {\bf 12}, 123 (2022). In addition to known results, we show that the hybridization gap decreases with the magnetic field which corresponds to the diamagnetism. Furthermore, we show that the amplitude of the de Haas-van Alphen is oscillating with inverse temperature with a period defined by a combination of the hybridization gap and magnetic field. We analytically obtain the position and the height of the first and dominant peak of these oscillations.

cond-mat.str-el↗

arXiv2024

d-Wave Hall effect and linear magnetoconductivity in metallic collinear antiferromagnets

In this paper we theoretically predict a distinct class of anomalous Hall effects occurring in metallic collinear antiferromagnets. The effect is quadratic and $d-$wave symmetric in external magnetic field. In addition, the electric current, transverse to the current voltage drop and the magnetic field in the predicted effect are all in the same plane. Studied theoretical model consists of two-dimensional fermions interacting with the Néel order through momentum dependent exchange interaction having a $d-$wave symmetry. We also find unusual linear magnetoconductivity in this model. \end{abstract}

cond-mat.mes-hall↗

arXiv2022

Dirac magnons pairing via pumping

We study pumping of magnons to the Dirac points of magnon's Brillouin zone of a ferromagnet on a honeycomb lattice. In particular, we consider second-order Suhl process, when due to interaction between magnons, a pair of magnons is created due to absorption of two electromagnetic wave quanta. We introduce a bosonic analog of the Cooper ladder for the magnon pair, which is shown to enhance the pairing of magnons at the Dirac points. As a result of pairing of the Dirac magnons, the system becomes unstable towards formation of a magnetic state with zero or reduced magnetization - the Dirac magnon paired state. In this case the resonant frequency of the pump equals to that of energy of the Dirac points. Our estimates suggest that the Dirac magnon paired state can be found in the CrBr$_{3}$ or CrCl$_{3}$ ferromagnet below in vicinity of the Curie temperature.

cond-mat.mes-hall↗

arXiv2022

Linear magnetoconductivity in magnetic metals

We theoretically describe a mechanism of low-field linear magnetoconductivity in helical magnetic metals. Two ingredients for the mechanism in three-dimensional metals are identified to be the spin-orbit coupling and momentum-dependent ferromagnetic exchange interaction. We propose and study a number of minimal theoretical models which have linear magnetoconductivity, and discuss their implications for recent experiments.

cond-mat.mes-hall↗

arXiv2022

Fluctuation-induced odd-frequency spin-triplet pairing in disordered electron liquid

We consider a two-dimensional disordered conductor in the regime when the superconducting phase is destroyed by the magnetic field. We analyze a combination of fluctuations of different origin which results in an effective interaction amplitude suitable for a spontaneous s-wave odd-frequency pairing instability. We observe that the end point of the superconductivity is a quantum critical point separating the conventional superconducting phase from a state with the odd-frequency spin-triplet pairing instability. We speculate that this could shed light on a rather mysterious insulating state observed in strongly disordered superconducting films in a broad region of the magnetic fields.

cond-mat.str-el↗

arXiv2022

Anisotropic resistivity and superconducting instability in ferroelectric metals

We propose a theoretical model of a ferroelectric metal where spontaneous electric polarization coexists with the conducting electrons. In our model we adopt a scenario when conducting electrons interact with two soft transverse optical phonons, generalize it to the case when there is a spontaneous ferroelectric polarization in the system, and show that a linear coupling to the phonons emerges as a result. We find that this coupling results in anisotropic electric transport which has a transverse to the current voltage drop. Importantly, the obtained transverse component of the resistivity has distinct linear dependence with temperature. Moreover, we show that the coupling enhances superconducting transition temperature of the ferroelectric metal. We argue that our results help to explain recent experiments on ferroelectric strontium titanate, as well as provide new experimental signatures to look for.

cond-mat.str-el↗

arXiv2021

On the magnetotransport of Weyl semimetals due to the chiral anomaly

We study electric field and temperature gradient driven magnetoconductivity of a Weyl semimetal system. To analyze the responses, we utilize the kinetic equation with semiclassical equations of motion modified by the Berry curvature and orbital magnetization of the wave-packet. Apart from known positive quadratic magnetoconductivity, we show that due to chiral anomaly, the magnetconductivity can become non-analytic function of the magnetic field, proportional to 3/2 power of the magnetic field at finite temperatures. We also show that time-reversal symmetry breaking tilt of the Dirac cones results in linear magnetoconductivity. This is due to one-dimensional chiral anomaly the tilt is responsible for.

cond-mat.mes-hall↗

arXiv2020

In-plane Hall effect in two-dimensional helical electron systems

We study Berry curvature driven and Zeeman magnetic field dependent electric current responses of two-dimensional electron system with spin-orbit coupling. New non-dissipative component of the electric current occurring in the applied in-plane magnetic field is described. This component is transverse to the electric field, odd in the magnetic field, and depends only on one particular direction of the magnetic field defined by the spin-orbit coupling. We show that the effect can be observed in a number of systems with $C_{3v}$ symmetry.

cond-mat.mes-hall↗

arXiv2018

Nonlinear Chiral Transport in Dirac Semimetals

We study the current of chiral charge density in a Dirac semimetal with two Dirac points in momentum space, subjected to an externally applied time dependent electric field and in the presence of a magnetic field. Based on the kinetic equation approach, we find contributions to the chiral charge current, that are proportional to the second power of the electric field and to the first and second powers of the magnetic field, describing the interplay of the chiral anomaly and the drift motion of electrons moving under the action of electric and magnetic fields.

cond-mat.mes-hall↗