arXiv subjects

Vladimir A. Zyuzin

Publications and source records attributed to Vladimir A. Zyuzin.

30 records · Page 2Linked to original sources

arXiv2018

Chiral electric separation effect in Weyl semimetals

We study the chiral electric separation effect (CESE) in Weyl semimetals (WSM). Within the model based on the kinetic equation we show that there is a non-zero chirality current in external electric and magnetic fields. We distinguish longitudinal, in-plane transverse, Hall, and anomalous Hall components of the CESE. It is shown that the first two components are quadratic in electric field and linear in magnetic field, while the Hall component is quadratic in both the electric and magnetic fields. All three are due to the chiral anomaly. In WSMs the chirality current can be associated with the spin current, which can be experimentally observed.

cond-mat.mes-hall↗

arXiv2018

Dynamical susceptibility of a Fermi liquid

We study the dynamic response of a Fermi liquid in the spin, charge and nematic channels beyond the random phase approximation for the dynamically screened Coulomb potential. In all the channels, one-loop order corrections to the irreducible susceptibility result in a non-zero spectral weight of the corresponding fluctuations above the particle-hole continuum boundary. It is shown that the imaginary part of the spin susceptibility, $\text{Im}χ_{s}(\bf{q},ω)$, falls off as $q^2/ω$ for frequencies above the continuum boundary ($ω\gg v_{F} q$) and below the model-dependent cutoff frequency, whereas the imaginary part of the charge susceptibility, $\text{Im}χ_c(\bf{q},ω)$, falls off as $(q/k_F)^2 q^2/ω$ for frequencies above the plasma frequency. An extra factor of $(q/k_F)^2$ in $\text{Im}χ_c(\bf{q},ω)$ as compared to $\text{Im}χ_{s}(\bf{q},ω)$ is a direct consequence of Galilean invariance. The imaginary part of the nematic susceptibility increases linearly with $ω$ up to a peak at the ultraviolet energy scale-- the plasma frequency and/or Fermi energy--and then decreases with $ω$. We also obtain explicit forms of the spin susceptibility from the kinetic equation in the collisionless limit and for the Landau function that contains up to first three harmonics.

cond-mat.str-el↗

arXiv2018

Spin Hall and Nernst effects of Weyl magnons

In this paper, we present a simple model of a three-dimensional insulating magnetic structure which represents a magnonic analog of the layered electronic system described in [Phys. Rev. Lett. {\bf 107}, 127205 (2011)]. In particular, our model realizes Weyl magnons as well as surface states with a Dirac spectrum. In this model, the Dzyaloshinskii-Moriya interaction is responsible for the separation of opposite Weyl points in momentum space. We calculate the intrinsic (due to the Berry curvature) transport properties of Weyl and so-called anomalous Hall effect (AHE) magnons. The results are compared with fermionic analogs.

cond-mat.mes-hall↗

arXiv2018

Pumping of magnons in a Dzyaloshinskii-Moriya ferromagnet

We formulate a microscopic linear response theory of nonequilibrium magnonic torques and magnon pumping applicable to multiple-magnonic-band uniform ferromagnets with Dzyaloshinskii-Moriya interactions. From the linear response theory, we identify the extrinsic and intrinsic contributions where the latter is expressed via the Berry curvature of magnonic bands. We observe that in the presence of a time-dependent magnetization Dzyaloshinskii-Moriya interactions can act as fictitious electric fields acting on magnons. We study various current responses to this fictitious field and analyze the role of Berry curvature. After identifying the magnon-mediated contribution to the equilibrium Dzyaloshinskii-Moriya interaction, we also establish the Onsager reciprocity between the magnon-mediated torques and heat pumping. We apply our theory to the magnonic heat pumping and torque responses in honeycomb and kagome lattice ferromagnets.

cond-mat.mes-hall↗

arXiv2017

Landau levels for electromagnetic wave

In this paper we show that the frequencies of propagating electromagnetic wave (photon) in rotating dielectric medium obey Landau quantization. We show that the degeneracy of right and left helicities of photons is broken on the lowest Landau level. In homogeneous space this level is shown to be helical, i.e. left and right helical photons counter-propagate. This leads to helical vortical effect for photons.

physics.optics↗

arXiv2016

Magnon spin Nernst effect in antiferromagnets

We predict that a temperature gradient can induce a magnon-mediated spin Hall response in an antiferromagnet with non-trivial magnon Berry curvature. We develop a linear response theory which gives a general condition for a Hall current to be well defined, even when the thermal Hall response is forbidden by symmetry. We apply our theory to a honeycomb lattice antiferromagnet and discuss a role of magnon edge states in a finite geometry.

cond-mat.mes-hall↗

arXiv2014

Dynamical spin structure factor of one-dimensional interacting fermions

We revisit the dynamic spin susceptibility, $χ(q,ω)$, of one-dimensional interacting fermions. To second order in the interaction, backscattering results in a logarithmic correction to $χ(q,ω)$ at $q\ll k_F$, even if the single-particle spectrum is linearized near the Fermi points. Consequently, the dynamic spin structure factor, $\mathrm{Im}χ(q,ω)$, is non-zero at frequencies above the single-particle continuum. In the boson language, this effect results from the marginally irrelevant backscattering operator of the sine-Gordon model. Away from the threshold, the high-frequency tail of $\mathrm{Im}χ(q,ω)$ due to backscattering is larger than that due to finite mass by a factor of $k_F/q$. We derive the renormalization group equations for the coupling constants of the $g$-ology model at finite $ω$ and $q$ and find the corresponding expression for $χ(q,ω)$, valid to all orders in the interaction but not in the immediate vicinity of the continuum boundary, where the finite-mass effects become dominant.

cond-mat.str-el↗

arXiv2013

Role of domain wall fluctuations in non-Fermi liquid behavior of metamagnets

We study resistivity temperature dependence of a three dimensional metamagnet near the metamagnet phase transition point in the case when magnetic structure tends to split into regions with high and low magnetization. We show that in the case of weak pinning the spin relaxation time of domain wall is much larger than that of the volume spin fluctuations. This opens a temperature range where resistivity temperature dependence is determined by scattering of conducting electrons by the domain wall fluctuations. We show that it leads to quasi-linear low temperature dependence of resistivity.

cond-mat.mes-hall↗

arXiv2012

Fractional Quantum Hall Effect from Phenomenological Bosonization

In this paper we propose a model of the fractional quantum Hall effect within conventional one-dimensional bosonization. It is shown that in this formalism the resulting bosonized fermion operator corresponding to momenta of Landau gauge wave function is effectively two-dimensional. At special filling factors the bulk gets gapped, and the theory is described by a sine-Gordon model. The edges are shown to be gapless, chiral, and carrying a fractional charge. The hierarchy of obtained fractional charges is consistent with existing experiments and theories. It is also possible to draw a connection to composite fermion description and to the Laughlin many-body wave function.

cond-mat.str-el↗

arXiv2012

Spatially anisotropic kagome antiferromagnet with Dzyaloshinskii-Moriya interaction

We theoretically study the spatially anisotropic spin-1/2 kagome antiferromagnet with Dzyaloshinskii-Moriya (DM) interaction using a renormalization group analysis in the quasi-one-dimensional limit. We identify the various temperature and energy scales for ordering in the system. For very weak DM interaction, we find a low-temperature spiral phase with the plane of the spiral selected by the DM interaction. This phase is similar to a previously identified phase in the absence of the DM interaction. However, above a critical DM interaction strength we find a transition to a phase with coexisting antiferromagnetic and dimer order, reminiscent of one-dimensional antiferromagnetic systems with a uniform DM interaction. Our results help shed light on the fate of two dimensional systems with both strong interactions and significant spin-orbit coupling.

cond-mat.str-el↗

arXiv2010

Coulomb drag between helical edge states

We theoretically investigate the Coulomb drag between the edge states of two quantum spin Hall systems. Using an interacting theory of the one-dimensional helical edge modes, we show that the drag vanishes at second order in the inter-edge interaction, where it is typically finite in other systems, due to the absence of backscattering within the edges. However, in the presence of a small external magnetic field the drag is finite and scales as the fourth power of the magnetic field, a behavior that sharply distinguishes it from other systems. We obtain the temperature dependence of the drag for regimes of both linear and quadratic edge dispersion in the presence of a finite field.

cond-mat.str-el↗

arXiv2007

Effect of electron interactions on the conductivity and exchange coupling energy of disordered metallic magnetic multilayer

We consider the effect of electron-electron interactions on the current-in-plane (CIP) conductivity and exchange coupling energy of a disordered metallic magnetic multilayer. We analyze its dependence on the value of ferromagnetic splitting of conducting electrons and ferromagnetic layers relative magnetizations orientation. We show that contribution to the CIP conductivity and exchange coupling energy as a periodic function of the angle of magnetizations relative orientation experience $ 2π\to π$ transition depending on the characteristic energies: ferromagnetic splitting of the conducting electrons and the Thouless energy of paramagnetic layer.

cond-mat.mes-hall↗