Results for "M. I. Katsnelson"

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Aharonov-Bohm effect in undoped graphene: Magnetotransport via evanescent wavesNov 17 2009Using conformal mapping technique, compact and general analytic expressions for the effects of magnetic fluxes on conductance and Fano factor of undoped graphene nanoflakes in pseudodiffusive regime are derived.
Conductance quantization in graphene nanoribbons: Adiabatic approximationMar 07 2007May 30 2007A theory of electron states for graphene nanoribbons with a smoothly varying width is developed. It is demonstrated that the standard adiabatic approximation allowing to neglect the mixing of different standing waves is more restrictive for the massless ... More
Graphene: carbon in two dimensionsDec 20 2006Carbon is one of the most intriguing elements in the Periodic Table. It forms many allotropes, some being known from ancient times (diamond and graphite) and some discovered ten to twenty years ago (fullerenes, nanotubes). Quite interestingly, the two-dimensional ... More
Minimal conductivity in bilayer grapheneJun 23 2006Using the Landauer formula approach, it is proven that minimal conductivity of order of $e^{2}/h$ found experimentally in bilayer graphene is its intrinsic property. For the case of ideal crystals, the conductivity turns our to be equal to $e^{2}/2h$ ... More
Quantum transport via evanescent waves in undoped grapheneJan 13 2011Charge carriers in graphene are chiral quasiparticles ("massless Dirac fermions"). Graphene provides therefore an amazing opportunity to study subtle quantum relativistic effects in condensed matter experiment. Here I review a theory of one of these unusual ... More
Comment on "Projective Quantum Monte Carlo Method for the Anderson Impurity Model and its Application to Dynamical Mean Field Theory"Aug 31 2005Apr 05 2006A comment about importance of Anderson's orthogonality catastrophe for projective Quantum Monte Carlo methods.
Optical properties of graphene: the Fermi liquid approachSep 05 2008Optical properties of two-dimensional massless Dirac fermions are considered by the formalism of pseudospin precession equations which provides an easy and natural semiphenomenological way to include correlation effects. It is shown that the latter are ... More
Nonlinear screening of charge impurities in grapheneSep 01 2006Nov 05 2006It is shown that a ``vacuum polarization'' induced by Coulomb potential in graphene leads to a strong suppression of electric charges even for undoped case (no charge carriers). A standard linear response theory is therefore not applicable to describe ... More
Zitterbewegung, chirality, and minimal conductivity in grapheneDec 15 2005Jun 11 2006It has been recently demonstrated experimentally that graphene, or single-layer carbon, is a gapless semiconductor with massless Dirac energy spectrum. A finite conductivity per channel of order of $e^{2}/h$ in the limit of zero temperature and zero charge ... More
Flexuron, a self-trapped state of electron in crystalline membranesOct 25 2010Nov 10 2010Self-trapping of an electron due to its interaction with bending fluctuations in a flexible crystalline membrane is considered. Due to the dependence of the electron energy on the corrugations of the membrane, the electron can create around itself an ... More
Coulomb drag in graphene single layers separated by a thin spacerMay 12 2011Jul 23 2011Motivated by very recent studies of Coulomb drag in grahene-BN-graphene system we develop a theory of Coulomb drag for the Fermi liquid regime, for the case when the ratio of spacer thickness $d$ to the Fermi wavelength of electrons is arbitrary. The ... More
Scattering of charge carriers by point defects in bilayer grapheneJun 10 2007Sep 02 2007Theory of scattering of massive chiral fermions in bilayer graphene by radial symmetric potential is developed. It is shown that in the case when the electron wavelength is much larger than the radius of the potential the scattering cross-section is proportional ... More
Metal-Insulator Transition in Graphene on Boron NitrideJan 29 2014Aug 15 2014Electrons in graphene aligned with hexagonal boron nitride are modelled by Dirac fermions in a correlated random-mass landscape subject to a scalar- and vector-potential disorder. We find that the system is insulating in the commensurate phase since the ... More
Generalized kinetic equations for charge carriers in grapheneJul 19 2007Oct 19 2007A system of generalized kinetic equations for the distribution functions of two-dimensional Dirac fermions scattered by impurities is derived in the Born approximation with respect to short-range impurity potential. It is proven that the conductivity ... More
Probing of the Kondo peak by the impurity charge measurementApr 13 2005Jul 18 2005We consider the real-time dynamics of the Kondo system after the local probe of the charge state of the magnetic impurity. Using the exactly solvable infinite-degeneracy Anderson model we find explicitly the evolution of the impurity charge after the ... More
Many body renormalization of the minimal conductivity in grapheneJul 23 2013The conductance of ballistic graphene at the neutrality point is due to coherent electron tunneling between the leads, the so called pseudodiffusive regime. The conductance scales as function of the sample dimensions in the same way as in a diffusive ... More
Solvent Driven Formation of Bolaamphiphilic VesiclesDec 09 2005We show that a spontaneous bending of single layer bolaamphiphiles results from the frustration due to the competition between core-core and tail-solvent interactions. We find that spherical vesicles are stable under rather general assumptions on these ... More
Friedel oscillations at the surfaces of rhombohedral $N$-layer grapheneOct 06 2015Jan 12 2016The low-energy physics of rhombohedral $N$-layer graphene mainly arises on the external layers, where most of the {\pi} electrons are located. Their Bloch band structure defines a two-band semimetal; the dispersion relation scales as $\pm q^{N}$ with ... More
Transport through evanescent waves in ballistic graphene quantum dotsApr 15 2008Sep 19 2008We study the transport through evanescent waves in graphene quantum dots of different geometries. The transmission is suppressed when the leads are attached to edges of the same majority sublattice. Otherwise, the transmission depends exponentially on ... More
The Effective Spin Hamiltonian and Phase Separation Instability of the Almost Half-Filled Hubbard Model and Narrow-Band {\it S-f} ModelNov 08 2008The effective spin Hamiltonian is constructed in the framework of the almost half-filled Hubbard model on the Cayley tree by means of functional integral technique with the use of static approximation. The system in the ground state appears to be consisting ... More
Electron self-trapping at quantum and classical critical pointsFeb 21 2006Using Feynman path integral technique estimations of the ground state energy have been found for a conduction electron interacting with order parameter fluctuations near quantum critical points. In some cases only \textit{singular} perturbation theory ... More
Electron self-trapping and fluctuation density-of-states tail at the critical pointAug 14 2005We consider electron self-trapping due to its interaction with order-parameter fluuctuations at the second-order phase-transition or critical point (for example, at the Curie temperature in magnetic or ferroelectric semiconductors). Using Feynman path ... More
Magnetic susceptibility, exchange interactions and spin-wave spectra in the local spin density approximationJun 21 2004Starting from exact expression for the dynamical spin susceptibility in the time-dependent density functional theory a controversial issue about exchange interaction parameters and spin-wave excitation spectra of itinerant electron ferromagnets is reconsidered. ... More
Ab initio calculations of quasiparticle band structure in correlated systems: LDA++ approachJul 11 1997We discuss a general approach to a realistic theory of the electronic structure in materials containing correlated d- or f- electrons. The main feature of this approach is the taking into account the energy dependence of the electron self-energy with ... More
Antiferromagnetism and d-wave superconductivity in cuprates: a uster DMFT studyNov 20 1999We present a new approach to investigate the coexistence of antiferromagnetism and d-wave superconductivity in the two dimensional extended Hubbard model within a numerically exact cluster dynamical mean-field approximation. Self-consistent solutions ... More
First- principle calculations of magnetic interactions in correlated systemsApr 29 1999We present a novel approach to calculate the effective exchange interaction parameters based on the realistic electronic structure of correlated magnetic crystals in local approach with the frequency dependent self energy. The analog of ``local force ... More
LDA++ approach to electronic structure of magnets: correlation effects in ironAug 10 1998A novel approach to investigation of correlation effects in the electronic structure of magnetic crystals which takes into account a frequency dependence of the self energy (so called ``LDA++ approach'') is developed. The fluctuation exchange approximation ... More
Electronic structure and magnetic properties of correlated metals: A local self-consistent perturbation schemeApr 25 2002In the framework of ab initio dynamical mean field theory for realistic electronic structure calculations a new perturbation scheme which combine the T-matrix and fluctuating exchange approximations has been proposed. This method is less computationally ... More
Theory of optically forbidden d-d transitions in strongly correlated crystalsAug 31 2010A general multiband formulation of linear and non-linear optical response functions for realistic models of correlated crystals is presented. Dipole forbidden d-d optical transitions originate from the vertex functions, which we consider assuming locality ... More
Magnetism of correlated systems: beyond LDAMar 19 2001A novel approach to electronic correlations in magnetic crystals which takes into account a dynamical many-body effects is present. In order to to find a frequency dependence of the electron self energy, an effective quantum-impurity many-particle problem ... More
Zero-energy states in corrugated bilayer grapheneFeb 11 2008Feb 14 2008Anomalous quantum Hall effects in single-layer and bilayer graphene are related with nontrivial topological properties of electron states (Berry phases $\pi$ and 2$\pi$, respectively). It was known that the Atiyah-Singer index theorem guarantees, for ... More
Diamagnetism of metallic nanoparticles as the result of strong spin-orbit interactionMar 13 2019Mar 14 2019The magnetic susceptibility of an ensemble of clean metallic nanoparticles is shown to change from paramagnetic to diamagnetic one with the onset of spin-orbit interaction. The effect is quantified on the basis of symmetry analysis with the help of the ... More
First-principles Theory of Nonlocal Screening in GrapheneJun 12 2010Using the quasiparticle self-consistent GW (QSGW) and local-density (LD) approximations, we calculate the q-dependent static dielectric function, and derive an effective 2D dielectric function corresponding to screening of point charges. In the q-to-0 ... More
High-temperature ferromagnetism of $sp$ electrons in narrow impurity bands: Application to CaB$_6$May 21 2006Ferromagnetism with high Curie temperature $T_c$, well above room temperature, and very small saturation moment has been reported in various carbon and boron systems. It is argued that the magnetization must be very inhomogeneous with only a small fraction ... More
Magnetism and interaction-induced gap opening in graphene with vacancies or hydrogen adatoms: Quantum Monte Carlo studyFeb 04 2015May 22 2015We study electronic properties of graphene with finite concentration of vacancies or other resonant scatterers by a straightforward lattice Quantum Monte Carlo calculations. Taking into account realistic long-range Coulomb interaction we calculate distribution ... More
Landau levels of single layer and bilayer phosphoreneApr 09 2015In this work we introduce a low-energy Hamiltonian for single layer and bilayer black phosphorus that describes the electronic states at the vicinity of the gamma point. The model is based on a recently proposed tight-binding description for electron ... More
Diamagnetism of metallic nanoparticles as the result of strong spin-orbit interactionMar 13 2019The magnetic susceptibility of an ensemble of clean metallic nanoparticles is shown to change from paramagnetic to diamagnetic one with the onset of spin-orbit interaction. The effect is quantified on the basis of symmetry analysis with the help of the ... More
Topological matter: graphene and superfluid 3HeOct 14 2013Jan 14 2014Physics of graphene and physics of superfluid phases of 3He have many common features. Both systems are topological materials where quasiparticles behave as relativistic massless (Weyl, Majorana or Dirac) fermions. We formulate the points where these ... More
A new route towards uniformly functionalized single-layer grapheneMar 19 2010It is shown, by DFT calculations, that the uniform functionalization of upper layer of graphite by hydrogen or fluorine does not change essentially its bonding energy with the underlying layers, whereas the functionalization by phenyl groups decreases ... More
Enhancement of chemical activity in corrugated grapheneMay 13 2009Jun 22 2009Simulation of chemical activity of corrugated graphene within density functional theory predicts an enhancement of its chemical activity if the ratio of height of the corrugation (ripple) to its radius is larger than 0.07. Further growth of the curvature ... More
Spin and orbital ferromagnetism in strongly correlated itinerant electron systemsApr 12 2005Jul 05 2005Spectra of one-electron and collective excitations in narrow-band ferromagnets with unquenched orbital moments are calculated in various theoretical models. The interaction of spin and orbital excitations with conduction electrons results in the damping ... More
Scaling picture of magnetism formation in the anomalous f-systems: interplay of the Kondo effect and spin dynamicsMar 12 1997Formation of magnetically ordered state in the Kondo lattices is treated within the degenerate $s-f$ exchange and Coqblin-Schrieffer models. The Kondo renormalizations of the effective coupling parameter, magnetic moment and spin excitation frequencies ... More
Non-quasiparticle states in the core level spectra of ferromagnetic semiconductors and half-metallic ferromagnetsJan 30 2004Jul 05 2005The Green's functions that determine x-ray spectra are calculated in the s-d exchange model of a saturated conducting ferromagnet in the presence of the core hole. A possibility to observe non-quasiparticle (NQP) states in the core level (x-ray absorption, ... More
Nonperturbative anharmonic phenomena in crystal lattice dynamicsJan 23 2004Slow dynamics of energy transfer between different phonon modes under the resonance conditions is considered. It may result in new effects in the inelastic and quasielastic neutron scattering spectra.
Electron spectrum, thermodynamics and transport in antiferromagnetic metals at low temperaturesDec 20 1999Electron spectrum of 2D and 3D antiferromagnetic metals is calculated with account of spin-fluctuation corrections within perturbation theory in the s-f exchange model. Effects of the interaction of conduction electrons with spin waves in thermodynamic ... More
Gaps tunable by electrostatic gates in strained grapheneDec 04 2010May 28 2011We show that when the pseudomagnetic fields created by long wavelength deformations are appropriately coupled with a scalar electric potential, a significant energy gap can emerge due to the formation of a Haldane state. Ramifications of this physical ... More
The Aharonov-Bohm effect for massless Dirac fermions and the spectral flow of Dirac type operators with classical boundary conditionsApr 10 2012May 24 2012We compute, in topological terms, the spectral flow of an arbitrary family of self-adjoint Dirac type operators with classical (local) boundary conditions on a compact Riemannian manifold with boundary under the assumption that the initial and terminal ... More
One-dimensional spinless fermion model with competing interactions beyond half-fillingSep 15 2000An accurate numerical consideration of 1D spinless fermion model with next-nearest neighbour (NNN) interactions is carried out for the electron concentrations 4/7. It is shown that depending on the parameters of the model it can be either Luttinger liquid ... More
Breakdown of Luttinger liquid state in one-dimensional frustrated spinless fermion modelOct 13 1999Haldane hypothesis about the universality of Luttinger liquid (LL) behavior in conducting one-dimensional (1D) fermion systems is checked numerically for spinless fermion model with next-nearest-neighbor interactions. It is shown that for large enough ... More
Possible scenario of the melting of metalsJun 26 1999A microscopic picture of the ``preparation'' of a crystal to the transition to liquid state at the approach to melting temperature is proposed. Basing on simple crystallogeometric considerations and the analysis of the computational results for corresponding ... More
Electron energy level statistics in graphene quantum dotsApr 17 2008Oct 22 2008Motivated by recent experimental observations of size quantization of electron energy levels in graphene quantum dots \cite{ponomarenko} we investigate the level statistics in the simplest tight-binding model for different dot shapes by computer simulation. ... More
Magnetic Correlations at Graphene EdgesNov 01 2007Magnetic zigzag edges of graphene are considered as a basis for novel spintronics devices despite the fact that no true long-range magnetic order is possible in one dimension. We study the transverse and longitudinal fluctuations of magnetic moments at ... More
Graphene in periodic deformation fields: dielectric screening and plasmonsJun 20 2012We consider the effect of periodic scalar and vector potentials generated by periodic deformations of the graphene crystal lattice, on the energy spectrum of electrons. The dependence of electron velocity near the Dirac point on the periodic perturbations ... More
sp-Electron Magnetic Clusters with a Large Spin in GrapheneDec 17 2010Mar 05 2011Motivated by recent experimental data (Sepioni, M. et al. Phys. Rev. Lett. 2010, 105, 207205), we have studied the possibility of forming magnetic clusters with spin S> 1/2 on graphene by adsorption of hydrogen atoms or hydroxyl groups. Migration of hydrogen ... More
Quantum electrodynamics with anisotropic scaling: Heisenberg-Euler action and Schwinger pair production in the bilayer grapheneMar 07 2012Mar 19 2012We discuss quantum electrodynamics emerging in the vacua with anisotropic scaling. Systems with anisotropic scaling were suggested by Horava in relation to the quantum theory of gravity. In such vacua the space and time are not equivalent, and moreover ... More
Defect-induced ferromagnetism in fullerenesDec 18 2007Apr 05 2009Based on the ab initio electronic structure calculations the picture of ferromagnetism in polimerized C60 is proposed which seems to explain the whole set of controversial experimental data. We have demonstrated that, in contrast with cubic fullerene, ... More
Scaling theory of magnetic ordering in the Kondo lattices with anisotropic exchange interactionsMay 29 1998Jan 22 1999The lowest-order scaling consideration of the magnetic state formation in the Kondo lattices is performed within the $s-f$ model with inclusion of anisotropy for both the $f-f$ coupling and $s-f$ exchange interaction. The Kondo renormalizations of the ... More
Sum rules for X-ray magnetic circular dichroism spectra in strongly correlated ferromagnetsApr 21 2005Jul 05 2005It is proven that the sum rules for X-ray magnetic dichroism (XMCD) spectra that are used to separate spin and orbital contributions to the magnetic moment are formally correct for an arbitrary strength of electron-electron interactions. However, their ... More
Temperature dependences of resistivity and magnetoresistivity for half-metallic ferromagnetsApr 12 2002Peculiarities of transport properties of three- and two-dimensional half-metallic ferromagnets are investigated, which are connected with the absence of spin-flip scattering processes. The temperature and magnetic field dependences of resistivity in various ... More
Fermi liquid theory of electronic topological transitions and screening anomalies in metalsMay 09 1999Sep 27 1999General expressions for the contributions of the Van Hove singularity (VHS)in the electron density of states to the thermodynamic potential $\Omega are obtained in the framework of microscopic Fermi liquid theory. The renormalization of the singularities ... More
Graphene: new bridge between condensed matter physics and quantum electrodynamicsMar 14 2007Jun 06 2007Graphene is the first example of truly two-dimensional crystals - it's just one layer of carbon atoms. It turns out to be a gapless semiconductor with unique electronic properties resulting from the fact that charge carriers in graphene demonstrate charge-conjugation ... More
Quantum entanglement dynamics and decoherence wave in spin chains at finite temperaturesJul 28 2005We analyze the quantum entanglement at the equilibrium in a class of exactly solvable one-dimensional spin models at finite temperatures and identify a region where the quantum fluctuations determine the behavior of the system. We probe the response of ... More
Enhancement of the Curie temperature in small particles of weak itinerant ferromagnetsJun 01 2011Self consistent renormalization theory of itinerant ferromagnets is used to calculate the Curie temperature of clusters down to approximately 100 atoms in size. In these clusters the electrons responsible for the magnetic properties are assumed to be ... More
Spin-polarized scanning tunneling microscopy of half-metallic ferromagnets: Non-quasiparticle contributionsDec 12 2005The role of the many-body (spin-polaronic) effects in the scanning tunneling spectroscopy of half-metallic ferromagnets (HMF) is considered. It is shown that the non-quasiparticle (NQP) states exist in the majority or minority spin gap in the presence ... More
Exciton effects in a scaling theory of intermediate valence and Kondo systemsJan 26 2004An interplay of the Kondo scattering and exciton effects (d-f Coulomb interaction) in the intermediate valence systems and Kondo lattices is demonstrated to lead to an essential change of the scaling behavior in comparison with the standard Anderson model. ... More
Non-Fermi-liquid behavior in the Kondo lattices induced by peculiarities of magnetic ordering and spin dynamicsApr 06 1999Dec 01 1999A scaling consideration of the Kondo lattices is performed with account of singularities in the spin excitation spectral function. It is shown that a non-Fermi-liquid (NFL) behavior between two critical values of the bare $s-f$ coupling constant occurs ... More
The spin angular gradient approximation in the density functional theoryAug 21 2002A spin angular gradient approximation for the exchange correlation magnetic field in the density functional formalism is proposed. The usage of such corrections leads to a consistent spin dynamical approach beyond the local approximation. The proposed ... More
Misfit stabilized embedded nanoparticles in metallic alloysOct 26 2015Nanoscale inhomogeneities are typical for numerous metallic alloys and crucially important for their practical applications. At the same time, stabilization mechanisms of such a state are poorly understood. We present a general overview of the problem, ... More
Spin relaxation related to the edge scattering in grapheneApr 27 2014We discuss the role of spin-flip scattering of electrons from the magnetized edges in graphene nanoribbons. The spin-flip scattering is associated with strong fluctuations of the magnetic moments at the edge. Using the Boltzmann equation approach, which ... More
Edge scattering of electrons in grapheneSep 08 2013We discuss the contribution of edge scattering to the conductance of graphene nanoribbons and nanoflakes. Using different possible types of the boundary conditions for the electron wave function at the edge, we found dependences of the momentum relaxation ... More
Anomalous thermal expansion in $α$-titaniumJul 15 2007We provide a complete quantitative explanation for the anisotropic thermal expansion of hcp Ti at low temperature. The observed negative thermal expansion along the c-axis is reproduced theoretically by means of a parameter free theory which involves ... More
Destruction of graphene by metal adatomsApr 05 2009Jun 09 2009The formation energies for mono- and bivacancies in graphene in the presence of adatoms of various metals and small metallic clusters have been calculated. It is shown that transition metal impurities, such as iron, nickel and, especially, cobalt reduce ... More
Chemical functionalization of graphene with defectsJul 24 2008Jan 05 2009Defects change essentially not only electronic but also chemical properties of graphene being centers of its chemical activity. Their functionalization is a way to modify electronic and crystal structure of graphene which may be important for graphene-based ... More
Chemical functionalization of grapheneSep 30 2008Jan 05 2009Experimental and theoretical results on chemical functionalization of graphene are reviewed. Using hydrogenated graphene as a model system, general principles of the chemical functionalization are formulated and discussed. It is shown that, as a rule, ... More
Tuning the gap in bilyaer graphene using chemical functionalization: DFT calculationsFeb 28 2008Jul 24 2008Opening, in a controllable way, the energy gap in the electronic spectrum of graphene is necessary for many potential applications, including an efficient carbon-based transistor. We have shown that this can be achieved by chemical functionalization of ... More
Electron scattering on microscopic corrugations in grapheneJun 17 2007Sep 11 2007We discuss various scattering mechanisms for Dirac fermions in single-layer graphene. It is shown that scattering on a short-range potential (due to, for example, neutral impurities) is mostly irrelevant for electronic quality of graphene, which is likely ... More
Spin-wave contributions to nuclear magnetic relaxation in magnetic metalsApr 27 1999Jun 06 2000The longitudinal and transverse nuclear magnetic relaxation rates $1/T_1(T)$ and $1/T_2(T)$ are calculated for three- and two-dimensional (3D and 2D) metallic ferro- and antiferromagnets (FM and AFM) with localized magnetic moments in the spin-wave temperature ... More
Effective Hamiltonians for fastly driven many-body lattice systemsJan 02 2014Mar 05 2015We consider 1D lattices described by Hubbard or Bose-Hubbard models, in the presence of periodic high-frequency perturbations, such as uniform ac force or modulation of hopping coefficients. Effective Hamiltonians for interacting particles are derived ... More
On the phonon-induced superconductivity of disordered alloysNov 24 1997A model of alloy is considered which includes both quenched disorder in the electron subsystem (``alloy'' subsystem) and electron-phonon interaction. For given approximate solution for the alloy part of the problem, which is assumed to be conserving in ... More
Plaquette Valence Bond Theory of High-Temperature SuperconductivityApr 06 2016We present a strong-coupling approach to the theory of high-temperature superconductivity based on the observation of a quantum critical point in the plaquette within the t,t' Hubbard model. The crossing of ground state energies in the N=2,3,4 sectors ... More
Dual boson approach to collective excitations in correlated fermionic systemsMay 31 2011Dec 14 2011We develop a general theory of a boson decomposition for both local and non-local interactions in lattice fermion models which allows us to describe fermionic degrees of freedom and collective charge and spin excitations on equal footing. An efficient ... More
Nonquasiparticle states in half-metallic ferromagnetsJun 21 2004Anomalous magnetic and electronic properties of the half-metallic ferromagnets (HMF) have been discussed. The general conception of the HMF electronic structure which take into account the most important correlation effects from electron-magnon interactions, ... More
Spectral density functional approach to electronic correlations and magnetism in crystalsNov 05 2002A novel approach to electronic correlations and magnetism of crystals based on realistic electronic structure calculations is reviewed. In its simplest form it is a combination of the ``local density approximation'' (LDA) and the dynamical mean field ... More
Correlation effects in electronic structure of PuCoGa5Dec 07 2005We report on results of the first realistic electronic structure calculations of the Pu-based PuCoGa5 superconductor based on the dynamical mean field theory. We find that dynamical correlations due to the local Coulomb interaction between Pu f-electrons ... More
Electron Correlations and the Minority-Spin Band Gap in Half-Metallic Heusler AlloysJan 17 2006Electron-electron correlations affect the band gap of half-metallic ferromagnets by introducing non-quasiparticle states just above the Fermi level. In contrast to the spin-orbit coupling, a large asymmetric non-quasiparticle spectral weight is present ... More
Ab-initio study of the Coulomb interaction in NbxCo clusters: Strong on-site versus weak non-local screeningJan 10 2018By means of ab-initio calculations in conjunction with the random-phase approximation (RPA) within the full-potential linearized augmented plane wave method we study the screening of the Coulomb interaction in NbxCo (1<=x<=9) clusters. In addition, these ... More
Effect of magnetism on kinetics of "gamma"-"alpha" transformation and pattern formation in ironFeb 19 2013Feb 27 2013Kinetics of polymorphous "gamma"-"alfa" transformation in Fe is studied numerically within a model taking into account both lattice and magnetic degrees of freedom, based on first-principle calculations of the total energy for different magnetic states. ... More
Majority-spin non-quasiparticle states in half-metallic ferrimagnet Mn$_2$VAlFeb 18 2009The density of non-quasiparticle states in the ferrimagnetic full-Heuslers Mn$_2$VAl alloy is calculated from first principles upon appropriate inclusion of correlations. In contrast to most half-metallic compounds, this material displays an energy gap ... More
Transition metal ad-atoms on graphene: Influence of local Coulomb interactions on chemical bonding and magnetic momentsJul 15 2011We address the interaction of graphene with 3d transition metal adatoms and the formation of localized magnetic moments by means of first-principles calculations. By comparing calculations within the generalized gradient approximation (GGA) to GGA+U we ... More
Monovalent impurities on graphene: midgap states and migration barriersMar 11 2009Monovalent impurities on graphene can be divided into ionically and covalently bond impurities. The covalent impurities cause universal midgap states as the carbon atom next to the impurity is effectively decoupled from the graphene pi-bands. The electronic ... More
Autocatalytic mechanism of pearlite transformation in steelMay 24 2016Sep 04 2016A model of pearlite colony formation in carbon steels with ab-initio parameterization is proposed. The model describes the process of decomposition of austenite and cementite formation through a metastable intermediate structure by taking into account ... More
Hydrogen on graphene: Electronic structure, total energy, structural distortions, and magnetism from first-principles calculationsOct 10 2007Dec 28 2007Density functional calculations of electronic structure, total energy, structural distortions, and magnetism for hydrogenated single-layer, bilayer, and multi-layer graphene are performed. It is found that hydrogen-induced magnetism can survives only ... More
Dual fermion approach to nonlocal correlations in the Hubbard modelDec 07 2006May 10 2007A new diagrammatic technique is developed to describe nonlocal effects (e.g., pseudogap formation) in the Hubbard-like models. In contrast to cluster approaches, this method utilizes an exact transition to the dual set of variables, and it therefore becomes ... More
Finite-temperature magnetism of transition metals: an LDA+DMFT approachFeb 16 2001We present an ab initio quantum theory of the finite temperature magnetism of iron and nickel. A recently developed technique which combines dynamical mean-field theory with realistic electronic structure methods, successfully describes the many-body ... More
Intrinsic nanoscale inhomogeneity in ordering systems due to elastic-mediated interactionsJun 12 2007Oct 26 2007Phase diagram and pattern formation in two-dimensional Ising model with coupling between order parameter and lattice vibrations is investigated by Monte-Carlo simulations. It is shown that if the coupling is strong enough (or phonons are soft enough) ... More
Pseudomagnetic fields and ballistic transport in a suspended graphene sheetJul 20 2008We study a suspended graphene sheet subject to the electric field of a gate underneath. We compute the elastic deformation of the sheet and the corresponding effective gauge field, which modifies the electronic transport. In a clean system the two-terminal ... More
Gauge fields in grapheneMar 26 2010Jul 20 2010The physics of graphene is acting as a bridge between quantum field theory and condensed matter physics due to the special quality of the graphene quasiparticles behaving as massless two dimensional Dirac fermions. Moreover, the particular structure of ... More
A theoretical analysis of the chemical bonding and electronic structure of graphene interacting with Group IA and Group VIIA elementsJan 21 2010We propose a new class of materials, which can be viewed as graphene derivatives involving Group IA or Group VIIA elements, forming what we refer to as graphXene. We show that in several cases large band gaps can be found to open up, whereas in other ... More
Magnon activation by hot electrons via non-quasiparticle statesMar 23 2017We consider the situation when a femtosecond laser pulse creates a hot electron state in half-metallic ferromagnet (e. g. ferromagnetic semiconductor) on a picosecond timescale but do not act directly on localized spin system. We show that the energy ... More
Resonant optical second harmonic generation in graphene-based heterostructuresMar 15 2019An optical Second-Harmonic Generation (SHG) allows to probe various structural and symmetry-related properties of materials, since it is sensitive to the inversion symmetry breaking in the system. Here, we investigate the SHG response from a single layer ... More