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Adsorption of Alkali, Alkaline Earth and Transition Metal Atoms on SiliceneFeb 06 2013The adsorption characteristics of alkali, alkaline earth and transition metal adatoms on silicene, a graphene-like monolayer structure of silicon, are analyzed by means of first-principles calculations. In contrast to graphene, interaction between the ... More

Remarkable effect of stacking on the electronic and optical properties of few layer black phosphorusJun 15 2015The effect of the number of stacking layers and the type of stacking on the electronic and optical properties of bilayer and trilayer black phosphorus are investigated by using first principles calcula- tions within the framework of density functional ... More

Electronic and Vibrational Properties of PbI 2 : From Bulk to MonolayerJul 24 2018Using first-principles calculations, we study the dependence of the electronic and vibrational properties of multi-layered PbI 2 crystals on the number of layers and focus on the electronic-band structure and the Raman spectrum. Electronic-band structure ... More

Characterization of the size and position of electron-hole puddles at a graphene p-n junctionMar 24 2016The effect of an electron-hole puddle on the electrical transport when governed by snake states in a bipolar graphene structure is investigated. Using numerical simulations we show that information on the size and position of the electron-hole puddle ... More

Phonon hydrodynamics, thermal conductivity and second sound in 2D crystalsApr 12 2019Starting from our previous work where we have obtained a system of coupled integro-differential equations for acoustic sound waves and phonon density fluctuations in 2D crystals, we derive here the corresponding hydrodynamic equations and study their ... More

Superconducting proximity effect in graphene under inhomogeneous strainNov 19 2011The interplay between quantum Hall states and Cooper pairs is usually hindered by the suppression of the superconducting state due to the strong magnetic fields needed to observe the quantum Hall effect. From this point of view graphene is special since ... More

Magnetoconductance properties of rectangular arrays of spintronic quantum ringsJun 17 2008Electron transport through multi-terminal rectangular arrays of quantum rings is studied in the presence of Rashba-type spin-orbit interaction (SOI) and of a perpendicular magnetic field. Using the analytic expressions for the transmission and reflection ... More

Electronic, Optical and Mechanical Properties of Silicene DerivativesAug 10 2016Successful isolation of graphene from graphite opened a new era for material science and con- densed matter physics. Due to this remarkable achievement, there has been an immense interest to synthesize new two dimensional materials and to investigate ... More

Gate induced monolayer behavior in twisted bilayer black phosphorusSep 06 2017Optical and electronic properties of black phosphorus strongly depend on the number of layers and type of stacking. Using first-principles calculations within the framework of density functional theory, we investigate the electronic properties of bilayer ... More

Stone-Wales Defects in Silicene: Formation, Stability and Reactivity of Defect SitesJul 20 2013During the synthesis of ultra-thin materials with hexagonal lattice structure Stone-Wales (SW) type of defects are quite likely to be formed and the existence of such topological defects in the graphene-like structures results in dramatical changes of ... More

Tuning a Circular p-n Junction in Graphene from Quantum Confinement to Optical GuidingMay 20 2017The motion of massless Dirac-electrons in graphene mimics the propagation of photons. This makes it possible to control the charge-carriers with components based on geometrical-optics and has led to proposals for an all-graphene electron-optics platform. ... More

Realization of a Tunable Artificial Atom at a Supercritically Charged Vacancy in GrapheneAug 31 2015Apr 14 2016The remarkable electronic properties of graphene have fueled the vision of a graphene-based platform for lighter, faster and smarter electronics and computing applications. One of the challenges is to devise ways to tailor its electronic properties and ... More

Flat Bands in Buckled Graphene SuperlatticesApr 23 2019Interactions between stacked two-dimensional (2D) atomic crystals can radically change their properties, leading to essentially new materials in terms of the electronic structure. Here we show that monolayers placed on an atomically flat substrate can ... More

Quantum dot size dependent influence of the substrate orientation on the electronic and optical properties of InAs/GaAs quantum dotsSep 14 2006Using 3D k.p calculation including strain and piezoelectricity we predict variation of electronic and optical properties of InAs/GaAs quantum dots (QDs) with the substrate orientation. The QD transition energies are obtained for high index substrates ... More

Semi-classical magnetoresistance in weakly modulated magnetic fieldsJan 25 2000The semi-classical conductance of a two-dimensional electron gas is calculated in the presence of a one-dimensional modulated magnetic field with zero average. In the limit of small magnetic field amplitudes (B) the contribution of the magnetic modulation ... More

Enhanced Weiss oscillations in grapheneJan 09 2007The magneto-conductivity of a single graphene layer where the electrons are described by the Dirac Hamiltonian weakly modulated by a periodic potential is calculated. It is shown that Weiss oscillations periodic in the inverse magnetic field appear, that ... More

Tunable optical Aharonov-Bohm effect in a semiconductor quantum ringApr 13 2012By applying an electric field perpendicular to a semiconductor quantum ring we show that it is possible to modify the single particle wave function between quantum dot (QD)-like to ring-like. The constraints on the geometrical parameters of the quantum ... More

Quasi-bound states of quantum dots in single and bilayer grapheneNov 28 2007Dirac fermions interacting with a cylindrically symmetric quantum dot potential created in single and bilayer graphene are not confined but form quasi-bound states. The broadening of these quasi-bound states (i. e. the inverse of their lifetimes) decreases ... More

Pinning and depinning of a classic quasi-one-dimensional Wigner crystal in the presence of a constrictionNov 09 2005We studied the dynamics of a quasi-one-dimensional chain-like system of charged particles at low temperature, interacting through a screened Coulomb potential in the presence of a local constriction. The response of the system when an external electric ... More

Strain engineered graphene using a nanostructured substrate: II Pseudo-magnetic fieldsApr 28 2012The strain induced pseudo-magnetic field in supported graphene deposited on top of a nanostructured substrate is investigated by using atomistic simulations. Step, elongated trench, one dimensional barrier, spherical bubbles, Gaussian bump and Gaussian ... More

Effect of grain boundary on the buckling of graphene nanoribbonsMar 03 2012The buckling of graphene nano-ribbons containing a grain boundary is studied using atomistic simulations where free and supported boundary conditions are invoked. We found that when graphene contains a small angle grain boundary the buckling strains are ... More

Graphene on boron-nitride: Moiré pattern in the van der Waals energyApr 19 2014The spatial dependence of the van der Waals (vdW) energy between graphene and hexagonal boron-nitride (h-BN) is investigated using atomistic simulations. The van der Waals energy between graphene and h-BN shows a hexagonal superlattice structure identical ... More

Non-homogeneous magnetic field induced magnetic edge states and their transport in a quantum wireNov 27 2000The spectrum of magnetic edge states and their transport properties in the presence of a perpendicular non-homogeneous magnetic field in a quantum wire formed by a parabolic confining potential are obtained. Systems are studied where the magnetic field ... More

Electron-phonon bound state in grapheneJan 13 2012The fine structure of the Dirac energy spectrum in graphene induced by electron-optical phonon coupling is investigated in the portion of the spectrum near the phonon emission threshold. The derived new dispersion equation in the immediate neighborhood ... More

Field-enhanced critical parameters in magnetically nanostructured superconductorsApr 25 2005Within the phenomenological Ginzburg-Landau theory, we demonstrate the enhancement of superconductivity in a superconducting film, when nanostructured by a lattice of magnetic particles. Arrays of out-of-plane magnetized dots (MDs) extend the critical ... More

Strain engineered graphene using a nanostructured substrate: I DeformationsApr 28 2012Using atomistic simulations we investigate the morphological properties of graphene deposited on top of a nanostructured substrate. Sinusoidally corrugated surfaces, steps, elongated trenches, one dimensional and cubic barriers, spherical bubbles, Gaussian ... More

Nanoindentation of a circular sheet of bilayer grapheneMay 12 2011Nanoindentation of bilayer graphene is studied using molecular dynamics simulations. We compared our simulation results with those from elasticity theory as based on the nonlinear F\"{o}ppl-Hencky equations with rigid boundary condition. The force deflection ... More

Quantum transport in graphene Hall bars: Effects of vacancy disorderNov 24 2016Using the tight-binding model, we investigate the influence of vacancy disorder on electrical transport in graphene Hall bars in the presence of quantizing magnetic fields. Disorder, induced by a random distribution of monovacancies, breaks the graphene ... More

Magneto-optical transport properties of monolayer phosphoreneMay 26 2015Jul 22 2015The electronic properties of monolayer phosphorene are exotic due to its puckered structure and large intrinsic direct band gap. We derive and discuss its band structure in the presence of a perpendicular magnetic field. Further, we evaluate the magneto-optical ... More

Parallel magnetic field suppresses dissipation in superconducting nanostripsFeb 15 2018The motion of Abrikosov vortices in type-II superconductors results in a finite resistance in the presence of an applied electric current. Elimination or reduction of the resistance via immobilization of vortices is the "holy grail" of superconductivity ... More

Self-limiting growth of two-dimensional palladium between graphene oxide layersJun 07 2019The ability of different materials to display self-limiting growth has recently attracted enormous attention due to the importance of nanoscale materials in applications for catalysis, energy conversion, (opto)electronics, etc. Here, we show that electrochemical ... More

Magnetic field dependence of the energy of negatively charged excitons in semiconductor quantum wellsOct 30 2000A variational calculation of the spin-singlet and spin-triplet state of a negatively charged exciton (trion) confined to a single quantum well and in the presence of a perpendicular magnetic field is presented. We calculated the probability density and ... More

Stark effect on the exciton spectra of vertically coupled quantum dots: horizontal field orientation and non-aligned dotsDec 11 2006We study the effect of an electric-field on an electron-hole pair in an asymmetric system of vertically coupled self-assembled quantum dots taking into account their non-perfect alignment. We show that the non-perfect alignment does not qualitatively ... More

Electron spin and charge switching in a coupled quantum dot quantum ring systemJun 22 2004Few-electron systems confined in a quantum dot laterally coupled to a surrounding quantum ring in the presence of an external magnetic field are studied by exact diagonalization. The distribution of electrons between the dot and the ring is influenced ... More

Giant vortices in small mesoscopic disks: an approximate descriptionNov 19 2001We present an approximate description of the giant vortex state in a thin mesoscopic superconducting disk within the phenomenological Ginzburg-Landau approach. Analytical asymptotic expressions for the energies of the states with fixed vorticity are obtained ... More

Magnetoplasma excitations of two vertically coupled dotsDec 05 1997A classical hydrodynamic approach is used to calculate the magnetoplasma excitations of two vertically coupled electron dots. The electrons are confined by different parabolic potentials in which case Kohn's theorem is no longer valid. The equilibrium ... More

Ginzburg-Landau theory of the zig-zag transition in quasi-one-dimensional classical Wigner crystalsJul 18 2012We present a mean-field description of the zig-zag phase transition of a quasi-one-dimensional system of strongly interacting particles, with interaction potential $r^{-n}e^{-r/\lambda}$, that are confined by a power-law potential ($y^{\alpha}$). The ... More

Enhancement of the retrapping current of superconducting microbridges of finite lengthOct 06 2011We theoretically find that the resistance of a superconducting microbridge/nanowire {\it decreases} while the retrapping current $I_r$ for the transition to the superconducting state {\it increases} when one suppresses the magnitude of the order parameter ... More

Adsorption of H2O, NH3, CO, NO2, and NO on graphene: A first-principles studyOct 09 2007Motivated by the recent realization of graphene sensors to detect individual gas molecules, we investigate the adsorption of H2O, NH3, CO, NO2, and NO on a graphene substrate using first-principles calculations. The optimal adsorption position and orientation ... More

Dynamics of Vortex Shells in Mesoscopic Superconducting Corbino DisksOct 30 2006In mesoscopic superconducting disks vortices form shell structures as recently observed in Nb disks. We study the dynamics of such vortices, driven by an external current I_0, in a Corbino setup. At very low I_0, the system exhibits rigid body rotation ... More

Currents in a many-particle parabolic quantum dot under a strong magnetic fieldAug 31 2004Currents in a few-electron parabolic quantum dot placed into a perpendicular magnetic field are considered. We show that traditional ways of investigating the Wigner crystallization by studying the charge density correlation function can be supplemented ... More

Spin-dependent transmission through a chain of rings: influence of a periodically modulated spin-orbit interaction strength or ring radiusJul 20 2004We study ballistic electron transport through a finite chain of quantum circular rings in the presence of spin-orbit interaction of strength \alpha. For a single ring the transmission and reflection coefficients are obtained analytically and from them ... More

Stable and metastable states in a superconducting "eight" loop in applied magnetic fieldJan 30 2002The stable and metastable states of different configurations of a loop in the form of an eight is studied in the presence of a magnetic field. We find that for certain configurations the current is equal to zero for any value of the magnetic field leading ... More

Thermodynamic properties of the electron gas in multilayer graphene in the presence of a perpendicular magnetic fieldJan 06 2014The thermodynamic properties of the electron gas in multilayer graphene depend strongly on the number of layers and the type of stacking. Here we analyse how those properties change when we vary the number of layers for rhombohedral stacked multilayer ... More

Quantum states in a magnetic anti-dotJul 10 1998Jul 15 1998We study a new system in which electrons in two dimensions are confined by a non homogeneous magnetic field. The system consists of a heterostructure with on top of it a superconducting disk. We show that in this system electrons can be confined into ... More

Many-body effects in the cyclotron resonance of a magnetic dotSep 24 2009Intraband cyclotron resonance (CR) transitions of a two-electron quantum dot containing a single magnetic ion is investigated for different Coulomb interaction strengths and different positions of the magnetic ion. In contrast to the usual parabolic quantum ... More

Hamiltonian of a many-electron system with single-electron and electron-pair states in a two-dimensional periodic potentialJan 20 2015Based on the metastable electron-pair energy band in a two-dimensional (2D) periodic potential obtained previously by Hai and Castelano [J. Phys.: Condens. Matter 26, 115502 (2014)], we present in this work a Hamiltonian of many electrons consisting of ... More

Spin-dependent (magneto)transport through a ring due to spin-orbit interactionJul 20 2004Electron transport through a one-dimensional ring connected with two external leads, in the presence of spin-orbit interaction (SOI) of strength \alpha and a perpendicular magnetic field is studied. Applying Griffith's boundary conditions we derive analytic ... More

Flux penetration and expulsion in thin superconducting disksAug 18 1999Using an expansion of the order parameter over the eigenfunctions of the linearized first Ginzburg-Landau (GL) equation, we obtain numerically the saddle points of the free energy separating the stable states with different number of vortices. In contrast ... More

Influence of the confinement geometry on surface superconductivityMay 03 1999The nucleation field for surface superconductivity, $H_{c3}$, depends on the geometrical shape of the mesoscopic superconducting sample and is substantially enhanced with decreasing sample size. As an example we studied circular, square, triangular and ... More

Heating of quasiparticles driven by oscillations of the order parameter in short superconducting microbridgesMay 27 2011We predict 'heating' of quasiparticles driven by order parameter oscillations in the resistive state of short superconducting microbridges. The finite relaxation time of the magnitude of the order parameter $|\Delta|$ and the dependence of the spectral ... More

Rearrangement of the vortex lattice due to instabilities of vortex flowJun 08 2007With increasing applied current we show that the moving vortex lattice changes its structure from a triangular one to a set of parallel vortex rows in a pinning free superconductor. This effect originates from the change of the shape of the vortex core ... More

Symmetric and asymmetric states in mesoscopic superconducting wire in voltage driven regimeNov 13 2006Feb 09 2007The response of a mesoscopic homogeneous superconducting wire, connected with bulk normal metal reservoirs, is theoretically investigated as function of the applied voltage. The finite relaxation length of the nonequilibrium quasiparticle distribution ... More

Klein paradox for a pn junction in multilayer grapheneFeb 22 2013May 06 2013Charge carriers in single and multilayered graphene systems behave as chiral particles due to the particular lattice symmetry of the crystal. We show that the interplay between the meta-material properties of graphene multilayers and the pseudospinorial ... More

Excitons and charged excitons in semiconductor quantum wellsOct 27 2000A variational calculation of the ground-state energy of neutral excitons and of positively and negatively charged excitons (trions) confined in a single-quantum well is presented. We study the dependence of the correlation energy and of the binding energy ... More

Electron-phonon bound states in graphene in a perpendicular magnetic fieldJun 22 2012Nov 19 2012The spectrum of electron-phonon complexes in a monolayer graphene is investigated in the presence of a perpendicular quantizing magnetic field. Despite the small electron-phonon coupling, usual perturbation theory is inapplicable for calculation of the ... More

Strain controlled valley filtering in multi-terminal graphene structuresOct 31 2016Valley-polarized currents can be generated by local straining of multi-terminal graphene devices. The pseudo-magnetic field created by the deformation allows electrons from only one valley to transmit and a current of electrons from a single valley is ... More

Transition Between Ground State and Metastable States in Classical 2D AtomsJun 20 2001Structural and static properties of a classical two-dimensional (2D) system consisting of a finite number of charged particles which are laterally confined by a parabolic potential are investigated by Monte Carlo (MC) simulations and the Newton optimization ... More

Tunable circular dipolelike system in graphene: Mixed electron-hole statesApr 04 2019Coupled electron-hole states are realized in a system consisting of a combination of an electrostatic potential barrier and ring-shaped potential well, which resembles a circular dipole. A perpendicular magnetic field induces confined states inside the ... More

Cyclotron resonance of a magnetic quantum dotNov 18 2008The energy spectrum of a one-electron quantum dot doped with a single magnetic ion is studied in the presence of an external magnetic field. The allowed cyclotron resonance (CR) transitions are obtained together with their oscillator strength (OS) as ... More

Vibrational properties of nanographeneJan 28 2013The eigenmodes and the vibrational density of states of the ground state configuration of graphene clusters are calculated using atomistic simulations. The modified Brenner potential is used to describe the carbon-carbon interaction and carbon-hydrogen ... More

Mesoscopic field and current compensator based on a hybrid superconductor-ferromagnet structureAug 23 2005A rather general enhancement of superconductivity is demonstrated in a hybrid structure consisting of submicron superconducting (SC) sample combined with an in-plane ferromagnet (FM). The superconducting state resists much higher applied magnetic fields ... More

Magnetic Pinning of Vortices in a Superconducting Film: The (anti)vortex-magnetic dipole interaction energy in the London approximationJul 04 2002The interaction between a superconducting vortex or antivortex in a superconducting film and a magnetic dipole with in- or out-of-plane magnetization is investigated within the London approximation. The dependence of the interaction energy on the dipole-vortex ... More

Melting of graphene clustersApr 22 2013Density-functional tight-binding and classical molecular dynamics simulations are used to investigate the structural deformations and melting of planar carbon nano-clusters $C_{N}$ with N=2-55. The minimum energy configurations for different clusters ... More

Electronic properties of graphene nano-flakes: Energy gap, permanent dipole, termination effect and Raman spectroscopyFeb 05 2014The electronic properties of graphene nano-flakes (GNFs) with different edge passivation is investigated by using density functional theory. Passivation with F and H atoms are considered: C$_{N_c}$ X$_{N_x}$ (X=F or H). We studied GNFs with $10<N_c<56$ ... More

Iterated Gilbert Mosaics and Poisson Tropical Plane CurvesOct 26 2016We propose an iterated version of the Gilbert model, which results in a sequence of random mosaics of the plane. We prove that under appropriate scaling, this sequence of mosaics converges to that obtained by a classical Poisson line process with explicit ... More

Geodesics on Margulis spacetimesFeb 02 2011Aug 15 2011Let M be a Margulis spacetime whose associated complete hyperbolic surface S has compact convex core. Generalizing the correspondence between closed geodesics on M and closed geodesics on S, we establish an orbit equivalence between recurrent spacelike ... More

Electric field induced structural changes of water confined between two graphene layersJan 22 2016An external electric field changes the physical properties of polar-liquids due to the reorientation of their permanent dipoles. For example it should affect significantly the physical properties of water confined in a nanochannel. The latter effect is ... More

Magnetic Kronig-Penney model for Dirac electrons in single-layer grapheneJul 22 2009Jul 23 2009The properties of Dirac electrons in a magnetic superlattice (SL) on graphene consisting of very high and thin (delta-function) barriers are investigated. We obtain the energy spectrum analytically and study the transmission through a finite number of ... More

Plasmons and their interaction with electrons in trilayer grapheneJan 06 2014The interaction between electrons and plasmons in trilayer graphene is investigated within the Overhauser approach resulting in the 'plasmaron' quasi-particle. This interaction is cast into a field theoretical problem, nd its effect on the energy spectrum ... More

Interplay between snake and quantum edge states in a graphene Hall bar with a pn-junctionJul 29 2014Sep 09 2014The magneto- and Hall resistance of a locally gated cross shaped graphene Hall bar is calculated. The edge of the top gate is placed diagonally across the center of the Hall cross. Four-probe resistance is calculated using the Landauer-B\"uttiker formalism, ... More

Bilayer graphene Hall bar with a pn-junctionDec 04 2013We investigate the magnetic field dependence of the Hall and the bend resistances for a ballistic Hall bar structure containing a pn-junction sculptured from a bilayer of graphene. The electric response is obtained using the billiard model and we investigate ... More

Nano-engineered non-uniform strain in grapheneApr 28 2012Recent experiments showed that non-uniform strain can be produced by depositing graphene over pillars. We employed atomistic calculations to study the non-uniform strain and the induced pseudo-magnetic field up to 5000 Tesla in graphene on top of nano-pillars. ... More

Comment on "Impurity spectra of graphene under electric and magnetic fields"Jan 31 2018In a recent publication [Phys. Rev. B $\textbf{89}$, 155403 (2014)], the authors investigated the spectrum of a Coulomb impurity in graphene in the presence of magnetic and electric fields using the coupled series expansion approach. In the first part ... More

Helical liquid of snake statesMay 30 2013We derive an exact solution to the problem of spin snake states induced in a nonhomogeneous magnetic field by a combined action of the Rashba spin-orbit and Zeeman fields. In an antisymmetric magnetic field the spin snake states are nonlocal composite ... More

Correlation functions in electron-electron and electron-hole double quantum wells: Temperature, density and barrier-width dependenceJan 03 2019The classical-map hyper-netted-chain (CHNC) scheme, developed for treating fermion fluids at strong coupling and at finite temperatures, is applied to electron-electron and electron-hole double quantum wells. The pair distribution functions and the local ... More

Soft vortex matter in a type-I/type-II superconducting bilayerAug 26 2013Magnetic flux patterns are known to strongly differ in the intermediate state of type-I and type-II superconductors. Using a type-I/type-II bilayer we demonstrate hybridization of these flux phases into a plethora of unique new ones. Owing to a complicated ... More

Spatially-dependent sensitivity of superconducting meanders as single-photon detectorsJun 19 2012The photo-response of a thin current-carrying superconducting stripe with a 90-degree turn is studied within the time-dependent Ginzburg-Landau theory. We show that the photon acting near the inner corner (where the current density is maximal due to the ... More

Vortex configurations and critical parameters in superconducting thin films containing antidot arrays: Nonlinear Ginzburg-Landau theorySep 29 2006Using the non-linear Ginzburg-Landau (GL) theory, we obtain the possible vortex configurations in superconducting thin films containing a square lattice of antidots. The equilibrium structural phase diagram is constructed which gives the different ground-state ... More

Stabilization of vortex-antivortex configurations in mesoscopic superconductors by engineered pinningOct 24 2008Symmetry-induced vortex-antivortex configurations in superconducting squares and triangles were predicted earlier; yet, they have not been resolved in experiment up to date. Namely, with vortex-antivortex states being highly unstable with respect to defects ... More

Multi-vortex states of a thin superconducting disk in a step-like external magnetic fieldNov 22 2001The vortex states in a thin mesoscopic disk are investigated within the phenomenological Ginzburg-Landau theory in the presence of a step-like external magnetic field with zero average which could model the field resulting from a ferromagnetic disk or ... More

AA-stacked bilayer square ice between graphene layers?Sep 28 2015Water confined between two layers with separation of a few Angstrom forms layered two- dimensional ice structure. Using large scale molecular dynamics simulations with the adoptable ReaxFF interatomic potential we found that flat monolayer ice with a ... More

Scattering of Dirac electrons by circular mass barriers: valley filter and resonant scatteringNov 14 2011The scattering of two-dimensional (2D) massless Dirac electrons is investigated in the presence of a random array of circular mass barriers. The inverse momentum relaxation time and the Hall factor are calculated and used to obtain parallel and perpendicular ... More

Scattering of a Dirac electron on a mass barrierAug 07 2012The interaction of a wave packet (and in particular the wave front) with a mass barrier is investigated in one dimension. We discuss the main features of the wave packet that are inherent to two-dimensional wave packets, such as compression during reflection, ... More

Enhancement of electron-hole superfluidity in double few-layer grapheneJun 10 2014Dec 09 2014We propose two coupled electron-hole sheets of few-layer graphene as a new nanostructure to observe superfluidity at enhanced densities and enhanced transition temperatures. For ABC stacked few-layer graphene we show that the strongly correlated electron-hole ... More

Wigner crystallization in transition metal dichalcogenides: A new approach to correlation energyNov 11 2016We introduce a new approach for the correlation energy of one- and two-valley two-dimensional electron gas (2DEG) systems. Our approach is based on a random phase approximation at high densities and a classical approach at low densities, with interpolation ... More

Electric-field modulation of linear dichroism and Faraday rotation in few-layer phosphoreneNov 29 2018Electro-optical modulators, which use an electric voltage (or an electric field) to modulate a beam of light, are essential elements in present-day telecommunication devices. Using a self-consistent tight-binding approach combined with the standard Kubo ... More

Formation and Size-Dependence of Vortex Shells in Mesoscopic Superconducting Niobium DisksApr 10 2008Recent experiments [I.V. Grigorieva et al., Phys. Rev. Lett. 96, 077005 (2006)] on visualization of vortices using the Bitter decoration technique revealed vortex shells in mesoscopic superconducting Nb disks containing up to L=40 vortices. Some of the ... More

Quantum rings as electron spin beam splittersJul 27 2005May 08 2006Quantum interference and spin-orbit interaction in a one-dimensional mesoscopic semiconductor ring with one input and two output leads can act as a spin beam splitter. Different polarization can be achieved in the two output channels from an originally ... More

Microwave emission from a crystal of molecular magnets -- The role of a resonant cavityJun 28 2005Oct 24 2005We discuss the effects caused by a resonant cavity around a sample of a magnetic molecular crystal (such as Mn${}_{12}$-Ac), when a time dependent external magnetic field is applied parallel to the easy axis of the crystal. We show that the back action ... More

Carbonaceous molecules in the oxygen-rich circumstellar environment of binary post-AGB stars: C_{60} fullerenes and polycyclic aromatic hydrocarbonsOct 27 2011Context. The circumstellar environment of evolved stars is generally rich in molecular gas and dust. Typically, the entire environment is either oxygen-rich or carbon-rich, depending on the evolution of the central star. Aims. In this paper we discuss ... More

MgB2: superconductivity and pressure effectsApr 03 2002Jan 24 2003We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB$_{2}$. Experiments are proposed which lead to identification of the possible scenarios: whether both $\sigma $- and $\pi $-bands superconduct or $\sigma $% -alone. ... More

Mesoscopic superconducting disksDec 11 1998Dec 18 1998Using the non-linear Ginzburg-Landau (GL) eqs. type I superconducting disks of finite radius ($R$) and thickness ($d$) are studied in a perpendicular magnetic field. Depending on $R$ and $d$, first or second order phase transitions are found for the normal ... More

Tuning the electronic properties of gated multilayer phosphorene: A self-consistent tight-binding studyApr 13 2018By taking account of the electric-field-induced charge screening, a self-consistent calculation within the framework of the tight-binding approach is employed to obtain the electronic band structure of gated multilayer phosphorene and the charge densities ... More

Magnetic field dependence of electronic properties of MoS$_2$ quantum dots with different edgesFeb 26 2018Using the tight-binding approach, we investigate the energy spectrum of square, triangular and hexagonal MoS$_2$ quantum dots (QDs) in the presence of a perpendicular magnetic field. Novel edge states emerge in MoS$_2$ QDs, which are distributed over ... More

Ginzburg-Landau theory and effects of pressure on a two-band superconductor : application to MgB2Jan 24 2003We present a model of pressure effects of a two-band superconductor based on a Ginzburg-Landau free energy with two order parameters. The parameters of the theory are pressure as well as temperature dependent. New pressure effects emerge as a result of ... More

Radial fluctuations induced stabilization of the ordered state in two dimensional classical clustersDec 03 1999Melting of two dimensional (2D) clusters of classical particles is studied using Brownian dynamics and Langevin molecular dynamics simulations. The particles are confined by a circular hard wall or a parabolic external potential and interact through a ... More

Enhanced stability of the square lattice of a classical bilayer Wigner crystalAug 18 1999The stability and melting transition of a single layer and a bilayer crystal consisting of charged particles interacting through a Coulomb or a screened Coulomb potential is studied using the Monte-Carlo technique. A new melting criterion is formulated ... More

Melting of the classical bilayer Wigner crystal: influence of the lattice symmetryApr 28 1999The melting transition of the five different lattices of a bilayer crystal is studied using the Monte-Carlo technique. We found the surprising result that the square lattice has a substantial larger melting temperature as compared to the other lattice ... More

Normal modes of a quasi-one-dimensional multi-chain complex plasmaSep 21 2004We studied equally charged particles, suspended in a complex plasma, which move in a plane and interact with a screened Coulomb potential (Yukawa type) and with an additional external confining parabolic potential in one direction, that makes the system ... More