Dmitry A. Kuzmin

Hybridization of electromagnetic, spin and acoustic waves in magnetic having conical spiral ferromagnetic order

Abstract The spectrum of hybrid electromagnetic–spin–acoustic waves for magnetic having conical spiral ferromagnetic structure defined by heterogeneous exchange and relativistic interactions has been received. The possibility of resonant interaction of spin, electromagnetic and acoustic waves has been shown. The electromagnetic waves reflectance from the half-infinity layer of magnetic having conical spiral ferromagnetic order has been calculated for different values of external magnetic field (angle of spiral). The acoustic Faraday effect has been considered.

Transverse-electric plasmonic modes of cylindrical graphene-based waveguide at near-infrared and visible frequencies

Transverse-electric (TE) surface plasmons (SPs) are very unusual for plasmonics phenomenon. Graphene proposes a unique possibility to observe these plasmons. Due to transverse motion of carriers, TE SPs speed is usually close to bulk light one. In this work we discuss conditions of TE SPs propagation in cylindrical graphene-based waveguides. We found that the negativity of graphene conductivity’s imaginary part is not a sufficient condition. The structure supports TE SPs when the core radius of waveguide is larger than the critical value Rcr. Critical radius depends on the light frequency and the difference of permittivities inside and outside the waveguide. Minimum value of Rcr is comparable with the wavelength of volume wave and corresponds to interband carriers transition in graphene. We predict that use of multilayer graphene will lead to decrease of critical radius. TE SPs speed may differ more significantly from bulk light one in case of epsilon-near-zero core and shell of the waveguide. Results may open the door for practical applications of TE SPs in optics, including telecommunications.

Plasmonically induced magnetic field in graphene-coated nanowires.

In this Letter, we investigate a magnetic field induced by guiding plasmonic modes in graphene-coated nanowire via an inverse Faraday effect. Magnetic field distribution for different plasmonic modes has been calculated. It has been shown that a magnetic field has a vortex-like distribution for some plasmonic modes. The possibility of producing magnetic field distribution that rotates along the nanowire axis and periodically depends on azimuthal angle has been demonstrated.

Electromagnetic waves reflection, transmission and absorption by graphene–magnetic semiconductor–graphene sandwich-structure in magnetic field: Faraday geometry

Electrodynamic properties of the graphene - magnetic semiconductor - graphene sandwich-structure have been investigated theoretically with taking into account the dissipation processes. Influence of graphene layers on electromagnetic waves propagation in graphene - semi-infinte magnetic semiconductor and graphene - magnetic semiconductor - graphene sandwich-structure has been analyzed. Frequency and field dependences of the reflectance, transmittance and absorbtance of electromagnetic waves by such structure have been calculated. The size effects associated with the thickness of the structure have been analyzed. The possibility of efficient control of electrodynamic properties of graphene - magnetic semiconductor - graphene sandwich structure by an external magnetic field has been shown.

Electromagnetic Waves Reflectance of Graphene—Magnetic Semiconductor Superlattice in Magnetic Field

Electrodynamic properties of the graphene-magnetic semiconductor-graphene superlattice placed in magnetic field have been investigated theoretically in Faraday geometry, while taking into account dissipation processes. Frequency and field dependences of the reflectance, transmittance, and absorbtance of electromagnetic waves by such superlattice have been calculated for different numbers of periods of the structure and different sizes of the periods with using a transfer matrix method. The possibility of efficient control of electrodynamic properties of graphene-magnetic semiconductor-graphene superlattice has been shown.

Magnetic field control of plasmon polaritons in graphene-covered gyrotropic planar waveguide

In this Letter, we report about magnetic field switching of plasmon polaritons propagating into a planar gyrotropic waveguide covered by two graphene layers at a deeply subwavelength scale. It is shown that applying an external magnetic field may lead to energy redistribution between two waveguide surfaces. The effect value resonantly depends on the relation between waveguide size and exciting light wavelength. A change in chemical potential of graphene layers may be used for tuning the phase shift between plasmon polaritons at near-resonant wavelengths. Evident effect may be observed at low magnetic fields (less than one tesla) for wavelengths about microns on a scale of tens of nanometers. Such an effect may be used for plasmonics, photonics. and optoelectronics devices, as well as sensing applications.

Topologically Induced Optical Activity in Graphene-Based Meta-Structures

Non-reciprocity and asymmetric transmission in optical and plasmonic systems is a key element for engineering the one-way propagation structures for light manipulation. Here we investigate topological nanostructures covered with graphene-based meta-surfaces, which consist of a periodic pattern of sub-wavelength stripes of graphene winding around the (meta-) tube or (meta-)torus. We establish the relation between the topological and plasmonic properties in these structures, as justified by simple theoretical expressions. Our results demonstrate how to use strong asymmetric and chiral plasmonic responses to tailor the electrodynamic properties in topological meta-structures. Cavity resonances formed by elliptical and hyperbolic plasmons in meta-structures are sensitive to the one-way propagation regime in a finite length (Fabry-Perot-like) meta-tube and display the giant mode splitting in a (Mach-Zehnder-like) meta-torus.

Magnetoelectric susceptibility tensor of multiferroic TbMnO3 with cycloidal antiferromagnetic structure in external field

Magnetoelectric, dielectric, and magnetic susceptibility tensors of multiferroic TbMnO3 with cycloidal antiferromagnetic structure in external electric and magnetic fields have been investigated with taking into account dynamics of spin, electro-dipole, and acoustic subsystems. All components of tensors depend on values of external electric and magnetic fields. The possibility of control of electrodynamic properties of multiferroic TbMnO3 with cycloidal antiferromagnetic structure by external electric and magnetic fields has been shown. The resonant interaction of spin, electro-dipole, electromagnetic, and acoustic waves in such material is observed.

Plasmonics of magnetic and topological graphene-based nanostructures

Abstract Graphene is a unique material in the study of the fundamental limits of plasmonics. Apart from the ultimate single-layer thickness, its carrier concentration can be tuned by chemical doping or applying an electric field. In this manner, the electrodynamic properties of graphene can be varied from highly conductive to dielectric. Graphene supports strongly confined, propagating surface plasmon polaritons (SPPs) in a broad spectral range from terahertz to mid-infrared frequencies. It also possesses a strong magneto-optical response and thus provides complimentary architectures to conventional magneto-plasmonics based on magneto-optically active metals or dielectrics. Despite a large number of review articles devoted to plasmonic properties and applications of graphene, little is known about graphene magneto-plasmonics and topological effects in graphene-based nanostructures, which represent the main subject of this review. We discuss several strategies to enhance plasmonic effects in topologically distinct closed surface landscapes, i.e. graphene nanotubes, cylindrical nanocavities and toroidal nanostructures. A novel phenomenon of the strongly asymmetric SPP propagation on chiral meta-structures and the fundamental relations between structural and plasmonic topological indices are reviewed.

Modeling of Phase Transitions Kinetics in Systems with Two Interacting Order Parameters

We present common 1D model of first order phase transition based on coupled solution of order parameters evolution and heat transfer equations. Such a model may be used for simulation of phase transitions in multiferroics or magnetostructural phase transitions, for example. First order phase transition process has been described by Landau-Khalatnikov-like equation with the thermodynamic potential of 2-3-4 and 2-4-6 types.