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Evgenii E. Narimanov

Publications and source records attributed to Evgenii E. Narimanov.

At least 37 records · Page 2Linked to original sources
arXiv2014

Photonic Hyper-Crystals

We introduce a new "universality class" of artificial optical media - photonic hyper-crystals. These hyperbolic metamaterials with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals. In particular, surface waves supported by a hyper-crystal, possess the properties of both the optical Tamm states in photonic crystals and surface plasmon polaritons at the metal-dielectric interface.

physics.optics↗
arXiv2013

Self-assembled tunable photonic hyper-crystals

We demonstrate a novel artificial optical material, a photonic hyper-crystal, which combines the most interesting features of hyperbolic metamaterials and photonic crystals. Similar to hyperbolic metamaterials, photonic hyper-crystals exhibit broadband divergence in their photonic density of states due to the lack of usual diffraction limit on the photon wave vector. On the other hand, similar to photonic crystals, hyperbolic dispersion law of extraordinary photons is modulated by forbidden gaps near the boundaries of photonic Brillouin zones. Three dimensional self-assembly of photonic hyper-crystals has been achieved by application of external magnetic field to a cobalt nanoparticle-based ferrofluid. Unique spectral properties of photonic hyper-crystals lead to extreme sensitivity of the material to monolayer coatings of cobalt nanoparticles, which should find numerous applications in biological and chemical sensing.

physics.optics↗
arXiv2011

Beyond Stefan-Boltzmann Law: Thermal Hyper-Conductivity

We demonstrate that the broadband divergence of the photonic density of states in hyperbolic metamaterials leads to giant increase in radiative heat transfer, beyond the limit set by the Stefan-Boltzmann law. The resulting radiative thermal "hyper-conductivity" may approach or even exceed heat conductivity via electrons and phonons in regular solids.

physics.optics↗
arXiv2011

Chaos-assisted emission from asymmetric resonant cavity microlasers

We study emission from quasi-one-dimensional modes of an asymmetric resonant cavity that are associated with a stable periodic ray orbit confined inside the cavity by total internal reflection. It is numerically demonstrated that such modes exhibit directional emission, which is explained by chaos-assisted emission induced by dynamical tunneling. Fabricating semiconductor microlasers with the asymmetric resonant cavity, we experimentally demonstrate the selective excitation of the quasi-one-dimensional modes by employing the device structure to preferentially inject currents to these modes and observe directional emission in good accordance with the theoretical prediction based on chaos-assisted emission.

nlin.CD↗
arXiv2010

Metric Signature Transitions in Optical Metamaterials

We demonstrate that the extraordinary waves in indefinite metamaterials experience (- - + +) effective metric signature. During a metric signature change transition in such a metamaterial, a Minkowski space-time is "created" together with large number of particles populating this space-time. Such metamaterial models provide a table top realization of metric signature change events suggested to occur in Bose-Einstein condensates and quantum gravity theories.

physics.optics↗
arXiv2010

Chaos-assisted directional light emission from microcavity lasers

We study the effect of dynamical tunneling on emission from ray-chaotic microcavities by introducing a suitably designed deformed disk cavity. We focus on its high quality factor modes strongly localized along a stable periodic ray orbit confined by total internal reflection. It is shown that dominant emission originates from the tunneling from the periodic ray orbit to chaotic ones; the latter eventually escape from the cavity refractively, resulting in directional emission that is unexpected from the geometry of the periodic orbit, but fully explained by unstable manifolds of chaotic ray dynamics. Experimentally performing selective excitation of those modes, we succeeded in observing the directional emission in good agreement with theoretical prediction. This provides decisive experimental evidence of dynamical tunneling in a ray-chaotic microcavity.

nlin.CD↗
arXiv2007

Impedance-matched Hyperlens

We propose an approach to optical imaging beyond the diffraction limit, based on transformation optics in concentric circular cylinder domains. The resulting systems allow image magnification and minimize reflection losses due to the impedance matching at the input or output boundaries. While perfect impedance matching at both surfaces can only be obtained in a system with radius-dependent magnetic permeability, we demonstrate that comparable performance can be achieved in an optimized non-magnetic design.

physics.optics↗
arXiv2006

Nanowire metamaterials with extreme optical anisotropy

We study perspectives of nanowire metamaterials for negative-refraction waveguides, high-performance polarizers, and polarization-sensitive biosensors. We demonstrate that the behavior of these composites is strongly influenced by the concentration, distribution, and geometry of the nanowires, derive an analytical description of electromagnetism in anisotropic nanowire-based metamaterials, and explore the limitations of our approach via three-dimensional numerical simulations. Finally, we illustrate the developed approach on the examples of nanowire-based high energy-density waveguides and non-magnetic negative index imaging systems with far-field resolution of one-sixth of vacuum wavelength.

physics.optics↗
arXiv2005

Compact Quasi-Chaotic Optical Cavity

A novel, 3-dimensional, convex, multi-pass optical cavity with partially-chaotic ray dynamics is presented. The light is localized near stable, long-path length trajectories supported by the cavity, and beam diffraction is suppressed by the phase space barriers between the regions of regular and chaotic ray dynamics that are generally present in partially-chaotic systems. For a centimeter-size cavity, the design supports meter-scale optical path lengths, suggesting future applications in trace gas detection. An exemplary cavity has been fabricated from a hollow, gold-coated, acrylic shell. Our measurements using a HeNe laser and a pulsed red diode laser for characterization of the cavity beam pattern and optical path length, respectively, confirm the theoretically predicted optical dynamics and the ability of the cavity to support meter-scale path lengths.

physics.optics↗
arXiv2005

Non-magnetic nano-composites for optical and infrared negative refraction index media

We develop an approach to use nanostructured plasmonic materials as a non-magnetic negative-refractive index system at optical and near-infrared frequencies. In contrast to conventional negative refraction materials, our design does not require periodicity and thus is highly tolerant to fabrication defects. Moreover, since the proposed materials are intrinsically non-magnetic, their performance is not limited to proximity of a resonance so that the resulting structure has relatively low loss. We develop the analytical description of the relevant electromagnetic phenomena and justify our analytic results via numerical solutions of Maxwell equations.

physics.optics↗
arXiv2004

Resonant light interaction with plasmonic nanowire systems

We compare the optical response of isolated nanowires, double-wire systems, and Pi-structures, and show that their radiation is well described in terms of their electric and magnetic dipole moments. We also show that both dielectric permittivity and magnetic permeability can be negative at optical and near infrared frequencies, and demonstrate the connection between the geometry of the system and its resonance characteristics. We conclude that plasmonic nanowires can be employed for developing novel negative-index materials. Finally, we demonstrate that it is possible to construct a nanowire-based "transparent nanoresonator" with dramatically enhanced intensity and metal concentration below 5 %.

physics.optics↗
arXiv2004

Near-sighted superlens

We consider the problem of subwavelength imaging via a slab of a left handed media (LHM) in the presence of material losses. We derive the expression for the resolution limit of LHM-based lens and demonstrate that the area of its subwavelength performance is usually limited to the near-field zone.

physics.optics↗
arXiv2004

Non-magnetic left-handed material

We develop a new approach to build a material with negative refraction index. In contrast to conventional designs which make use of a resonant behavior to achieve a non-zero magnetic response, our material is intrinsically non-magnetic and relies on an anisotropic dielectric constant to provide a left-handed response in waveguide geometry. We demonstrate that the proposed material can support surface (polariton) waves, and show the connection between polaritons and the enhancement of evanescent fields, also referred to as super-lensing.

physics.optics↗
arXiv2003

Universal level-spacing distribution in quantum systems

Classical counterparts of a great variety of quantum systems, from atomic physics to quantum wells and quantum dots, to optical, microwave, and acoustic resonators exhibit partially chaotic dynamics. Since it is often impossible to measure the temporal dynamics in qunatum systems, the main and probably the most dramatic manifestation of classical chaos in their phase space is seen in the distribution of spacing between the neighboring energy levels. While the mechanism leading to the onset of chaotic dynamics is different in every system, the level spacing distribution obeys the universal law, changing from Poissonian in the completely integrable systems to Wigner in completely chaotic ones.

nlin.CD↗
arXiv2001

Sweeping of Lattice Disorder and Associated Phenomena in Colossal Magnetoresistance Compounds

We show through a variational calculation that in a large range of parameters the paramagnetic to ferromagnetic transition in colossal magnetoresistance compounds is accompanied by a collapse of polaronic lattice disorder in addition to that of spin disorder. The spin-lattice disordered state is shown to be localized and the ordered state itinerant as observed. The observed dramatic change in the diffuse scattering at the transition as well as the isotope effect are also explained.

cond-mat.str-el↗
arXiv2001

Semiclassical Theory of Coulomb Blockade Peak Heights in Chaotic Quantum Dots

We develop a semiclassical theory of Coulomb blockade peak heights in chaotic quantum dots. Using Berry's conjecture, we calculate the peak height distributions and the correlation functions. We demonstrate that the corrections to the corresponding results of the standard statistical theory are non-universal and can be expressed in terms of the classical periodic orbits of the dot that are well coupled to the leads. The main effect is an oscillatory dependence of the peak heights on any parameter which is varied; it is substantial for both symmetric and asymmetric lead placement. Surprisingly, these dynamical effects do not influence the full distribution of peak heights, but are clearly seen in the correlation function or power spectrum. For non-zero temperature, the correlation function obtained theoretically is in good agreement with that measured experimentally.

cond-mat.mes-hall↗