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Yuri S. Kivshar

Bio: Yuri S. Kivshar is an academic researcher from Australian National University. The author has contributed to research in topics: Metamaterial & Soliton. The author has an hindex of 126, co-authored 1845 publications receiving 79415 citations. Previous affiliations of Yuri S. Kivshar include Technische Universität Darmstadt & Los Alamos National Laboratory.


Papers
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Journal ArticleDOI
TL;DR: It is predicted that robust routing of slow-light pulses is possible between antisymmetrically coupled photonic-crystal waveguides and demonstrated that for all pulses with the group velocities varying by several orders of magnitude, the complete switching occurs at the fixed coupling length of just several unit cells of the photonic crystal.
Abstract: We suggest a novel and general approach to the design of photonic-crystal directional couplers operating in the slow-light regime. We predict, based on a general symmetry analysis, that robust tunneling of slow-light pulses is possible between antisymmetrically coupled photonic crystal waveguides. We demonstrate, through Bloch mode frequency-domain and finite-difference time-domain (FDTD) simulations that, for all pulses with strongly reduced group velocities at the photonic band-gap edge, complete switching occurs at a fixed coupling length of just a few unit cells of the photonic crystal.

26 citations

Book ChapterDOI
01 Jan 1994
TL;DR: In this paper, the authors show that the compacton's width is independent of the amplitude of the wave amplitude and the inverse pulse width, i.e., the width of compacton solitons with finite wavelength can be obtained in a proper continuum limit to discrete models.
Abstract: As is well-known, solitons appear in a result of a balance between weak nonlinearity and dispersion. However, when the wave dispersion is purely nonlinear, some novel features may be observed and the most remarkable one is the existence of the so-called compactons, i. e. solitons with finite wavelength recently discovered by Rosenau and Hyman1 for a special class of the Korteweg-de Vries (KdV) type equations with nonlinear dispersion. These travelling-wave solutions have a remarkable property: Unlike the standard KdV soliton which narrows as the amplitude increases, the compacton’s width is independent of the amplitude. Having the constant width, such solutions can not be obtained, however, in a result of a proper continuum limit to discrete models. Indeed, soliton-bearing partial differential equations may be derived from discrete models of solids in a result of expansions in the wave amplitude and inverse pulse width which normally need a scaling procedure. In other words, the continuum limit approach yields the condition of the slowly varying wave envelope which is consistent with the effect of weak nonlinearity balanced by a weak dispersion. As soon as we deal with compactons instead of standard solitons, the continuum limit approximation cannot be properly justified because higher-order derivatives will be only numerically small.

26 citations

Journal ArticleDOI
02 May 2014-Science
TL;DR: Yin et al. (4) open a new dimension in second-harmonic microscopy with the optical visualization of the edge modes in two-dimensional (2D), atomically thick materials.
Abstract: Nonlinear optics describes processes in which coherent photons change their properties, such as their frequency, when they pass through a medium. This field traces back to the demonstration of frequency doubling ( 1 )—generating photons with twice the frequency of the input laser light—via second-harmonic generation [(SHG); see the figure, panel A]. Because SHG is a second-order parametric process, the symmetry of the medium must lack inversion symmetry ( 2 ). Interfaces between bulk (or three-dimensional) materials can meet this criterion, which has made SHG microscopy an indispensable tool for their study ( 3 ). On page 488 of this issue, Yin et al. ( 4 ) open a new dimension in second-harmonic microscopy with the optical visualization of the edge modes in two-dimensional (2D), atomically thick materials ( 5 ).

26 citations

Journal ArticleDOI
TL;DR: In this paper, a two-dimensional magnetic metamaterial based on cut-wire pairs instead of split-ring resonators has been proposed for microwave frequency with lattice spacing around 10% of the free space wavelength.
Abstract: We study numerically and experimentally magnetic metamaterials based on cut-wire pairs instead of split-ring resonators. The cut-wire pair planar structure is extended in order to create a truly two-dimensional metamaterial suitable for scaling to optical frequencies. We fabricate the cut-wire metamaterial operating at microwave frequencies with lattice spacing around 10% of the free-space wavelength, and find good agreement with direct numerical simulations. Unlike the structures based on split-ring resonators, the nearest-neighbor coupling in cut-wire pairs can result in a magnetic stop-band with propagation in the transverse direction.

26 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigate multi-hump spatial solitary waves and multi-soliton patterns generated by an incoherent interaction of two optical beams in a medium with saturable (e.g. photorefractive) nonlinearity.
Abstract: We investigate multi-hump spatial solitary waves and multi-soliton patterns generated by an incoherent interaction of two optical beams in a medium with saturable (e.g. photorefractive) nonlinearity. Applying a bifurcation analysis and numerical relaxation technique, we reveal different scenarios of creating the multi-hump solitons and find the families of solitary waves composed of two mutually coupled components. We analyse the stability of these solitons to propagation and find that the evolution of a soliton is governed by its modal structure.

26 citations


Cited by
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08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

29,323 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations