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V. V. Klimov

Publications and source records attributed to V. V. Klimov.

17 recordsLinked to original sources
arXiv2016

Manipulation of polarization and spatial properties of light beams with chiral metafilms

Two-dimensional lattices of chiral nanoholes in a plasmonic film with lattice constants being slightly larger than light wavelength are proposed for effective control of polarization and spatial properties of light beams. Effective polarization conversion and strong circular dichroism in non-zero diffraction orders in these chiral metafilms are demonstrated by electromagnetic simulations. These interesting effects are found to result from interplay between radiation pattern of single chiral nanohole and diffraction pattern of the planar lattice, and can be manipulated by varying wavelength and polarization of incoming light as well as period of metastructure and refractive indexes of substrate and overlayer. Therefore, this work offers a novel paradigm for developing planar chiral metafilm-based optical devices with controllable polarization state, spatial orientation and intensity of outgoing light.

cond-mat.mes-hall↗
arXiv2011

Application of generalized method of eigenoscillations to problems of nanoplasmonics

A version of generalized eigenoscillation method is applied to the problem about resonant effects in metallic nanoparticles. An approach is proposed, that permits to avoid calculating all higher eigenoscillations except the resonant one. An algorithm for determination of the resonant eigenoscillation, based on the Galerkin procedure, is described in details for the case of bodies of revolution. Model numerical results are presented.

physics.optics↗
arXiv2010

Optical properties of a two-nanospheroid cluster: analytical approach

Optical properties of a plasmonic nano-antenna made of two metallic nanospheroids (prolate or oblate) are investigated analytically in quasistatic approximation. It is shown that in clusters of two nanospheroids, three types of plasmonic modes can be present. Two of them can be effectively excited by a plane electromagnetic wave, while the third one can be effectively excited only by a nanolocalized light source (an atom, a molecule, a quantum dot) placed in the gap between the nanoparticles. Analytical expressions for absorption and scattering cross-sections, enhancement of a local field, and radiative decay rate of a dipole source placed near such a nano-antenna are presented and analyzed.

physics.optics↗
arXiv2009

Novel approach to a perfect lens

Within the framework of an exact analytical solution of Maxwell equations in a space domain, it is shown that optical scheme based on a slab with negative refractive index ($n=-1$) (Veselago lens or Pendry lens) does not possess focusing properties in the usual sense . In fact, the energy in such systems does not go from object to its "image", but from object and its "image" to an intersection point inside a metamaterial layer, or vice versa. A possibility of applying this phenomenon to a creation of entangled states of two atoms is discussed.

physics.optics↗
arXiv2008

Plasmon oscillations in ellipsoid nanoparticles: beyond dipole approximation

The plasmon oscillations of a metallic triaxial ellipsoid nanoparticle have been studied within the framework of the quasistatic approximation. A general method has been proposed for finding the analytical expressions describing the potential and frequencies of the plasmon oscillations of an arbitrary multipolarity order. The analytical expressions have been derived for an electric potential and plasmon oscillation frequencies of the first 24 modes. Other higher orders plasmon modes are investigated numerically.

physics.optics↗
arXiv2008

Detecting of photons in optical fields of complicated spatial structure

We show that a photon detector, sensitive to the gradients of electromagnetic fields, or to magnetic fields, should be a useful tool to characterize the quantum properties of spatially-dependent optical fields. We discuss the excitation of an atom on a magnetic dipole or electric quadrupole transitions with the spiral photons of a Laguerre-Gauss (LG) or Bessel beams. We show that these beams are not true hollow beams, due to the presence of magnetic fields and gradients of electric fields on beam axis. This approach paves the way to an analysis at the quantum level of the spatial structure and angular momentum properties of singular light beams.

quant-ph↗
arXiv2008

Detection of Spiral photons in Quantum Optics

We show that a new type of photon detector, sensitive to the gradients of electromagnetic fields, should be a useful tool to characterize the quantum properties of spatially-dependent optical fields. As a simple detector of such a kind, we propose using magnetic dipole or electric quadrupole transitions in atoms or molecules and apply it to the detection of spiral photons in Laguerre-Gauss (LG) beams. We show that LG beams are not true hollow beams, due to the presence of magnetic fields and gradients of electric fields on beam axis. This approach paves the way to an analysis at the quantum level of the spatial structure and angular momentum properties of singular light beams.

quant-ph↗
arXiv2007

Plasmonic nature of van der Waals forces between nanoparticles

We propose a new approach to calculate van der Waals forces between nanoparticles where the van der Waals energy can be reduced to the energy of elementary surface plasmon oscillations in nanoparticles. The general theory is applied to describe the interaction between 2 metallic nanoparticles and between a nanoparticle and a perfectly conducting plane. Our results could be used to prove experimentally the existence of plasmonic molecules and to elaborate new control mechanisms for the adherence of nanoparticles between each other or onto surfaces.

cond-mat.other↗
arXiv2007

Plasmonic atoms and plasmonic molecules

The proposed paradigm of plasmonic atoms and plasmonic molecules allows one to describe and predict the strongly localized plasmonic oscillations in the clusters of nanoparticles and some other nanostructures in uniform way. Strongly localized plasmonic molecules near the contacting surfaces might become the fundamental elements (by analogy with Lego bricks) for a construction of fully integrated opto-electronic nanodevices of any complexity and scale of integration.

physics.optics↗
arXiv2006

Strongly localized plasmon oscillations in a cluster of two metallic nanospheres and their influence on spontaneous emission of an atom

The plasmon oscillations in a cluster of two metallic nanospheres are studied theoretically. Particular attention is paid to the case of nearly touching spheres. Simple analytical expressions have been found for the spectra of plasmon oscillations of different symmetry in this case. A new type of the plasmon oscillations, which are strongly localized between the spheres, and which totally disappear at separation of the spheres, has been discovered. The found plasmon oscillations have a dramatic effect on optical properties of an atom localized between the spheres.

physics.optics↗
arXiv2005

Laser nanotraps and nanotweezers for cold atoms: 3D gradient dipole force trap in the vicinity of Scanning Near-field Optical Microscope tip

Using a two-dipole model of an optical near-field of Scanning Near-field Optical Microscope tip, i. e. taking into account contributions of magnetic and electric dipoles, we propose and analyze a new type of 3D optical nanotrap found for certain relations between electric and magnetic dipoles. Electric field attains a minimum value in vacuum in the vicinity of the tip and hence such a trap is quite suitable for manipulations with cold atoms.

physics.optics↗
arXiv2005

Quadrupole transitions near interface: general theory and application to atom inside a planar cavity

Quadrupole radiation of an atom in an arbitrary environment is investigated within classical as well as quantum electrodynamical approaches. Analytical expressions for decay rates are obtained in terms of Green function of Maxwell equations. The equivalence of both approaches is shown. General expressions are applied to analyze the quadrupole decay rate of an atom placed between two half spaces with arbitrary dielectric constant. It is shown that in the case when the atom is close to the surface, the total decay rate is inversely proportional to the fifth power of distance between an atom and a plane interface.

physics.optics↗
arXiv2004

Radiative Decay Engineering by Triaxial Nanoellipsoids

Radiative decay rates of an atom placed near triaxial nanoellipsoid are investigated in long wavelength approximation. Analytical results are obtained in general case. It is shown that triaxial ellipsoid can be used for efficient control of decay rate of an atom, molecule or quantum dot. For example decay rate near silver ellipsoid can be enhanced by 5 orders of magnitude. It is also shown, that triaxial nanoellipsoid can be used for simultaneous efficient control of absorption and emission rates of fluorophores.

quant-ph↗
arXiv2003

Atom Nanooptics Based on Photon Dots and Photon Holes

New types of light fields localized in nanometer-sized regions of space were suggested and analyzed. The possibility of using these nanolocalized fields in atom optics for atom focusing and localization is discussed.

quant-ph↗
arXiv2002

Spontaneous emission rate of an excited atom placed near a nanofiber

The spontaneous decay rates of an excited atom placed near a dielectric cylinder are investigated. A special attention is paid to the case when the cylinder radius is small in comparison with radiation wavelength (nanofiber or photonic wire). In this case, the analytical expressions of the transition rates for different orientations of dipole are derived. It is shown that the main contribution to decay rates is due to quasistatic interaction of atom dipole momentum with nanofiber and the contributions of guided modes are exponentially small. On the contrary, in the case when the radius of fiber is only slightly less than radiation wavelength, the influence of guided modes can be substantial. The results obtained are compared with the case of dielectric nanospheroid and ideally conducting wire.

physics.atom-ph↗
arXiv2001

A Superdecay of an excited atom placed near ''Left-Handed'' sphere

The influence of a microsphere having a simultaneously negative permittivity and permeability (Left-Handed Sphere) on the decay rate of the allowed and forbidden transitions is considered. It is found, that in contrast to usual (Right-Handed) materials it is possible to increase the decay rate by several orders of magnitude even in the case of a sphere of small radii. This enhancement is due to the fact that there exist a new type of resonance modes (LH surface modes). The analytical expressions for resonance frequencies and associated quality factors of the new modes are found.

quant-ph↗