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We measure nonlinear optical scattering from individual Au nanorods excited by ultrafast laser pulses on resonance with their longitudinal plasmon mode. Isolating single rods removes inhomogeneous broadening and allows the measurement of a…

We have observed the propagation of an approximately 35 ns long light pulse with a negative group velocity through a laser-cooled 85Rb atomic medium. The anomalous dispersion results from linear atom-light interaction, and is unrelated to…

We present a procedure for the systematic estimation of the dispersion properties of linear discrete systems with periodic time-varying coefficients. The approach relies on the analysis of a single unit cell, making use of Bloch theorem…

经典物理 · 物理学 2017-08-23 Javier Vila , Raj Kumar Pal , Massimo Ruzzene , Giuseppe Trainiti

Atomic arrays provide an important quantum optical platform with photon-mediated dipoledipole interactions, which can be engineered to realize key applications in quantum information processing. A major obstacle for such application is the…

量子物理 · 物理学 2023-03-28 Luojia Wang , Da-Wei Wang , Luqi Yuan , Yaping Yang , Xianfeng Chen

We study theoretically the effect of ultraslow phase and group velocities in an anisotropic metamaterial. The ultraslow phase propagation is induced by the hyperbolic dispersion relation. While the inherent physics underlying the slow group…

光学 · 物理学 2007-05-23 Hailu Luo , Zhongzhou Ren , Weixing Shu , Fei Li

Numerical calculation of modes in dispersive and absorptive systems is performed using the finite element method. The dispersion is tackled in the frame of an extension of Maxwell's equations where auxiliary fields are added to the…

光学 · 物理学 2016-04-20 Yoann Brûlé , Guillaume Demésy , Boris Gralak

We study the energy propagation in subwavelength waveguides and demonstrate that the mechanism of material gain, previously suggested for loss compensation, is also a powerful tool to manipulate dispersion and propagation characteristics of…

光学 · 物理学 2007-05-23 Alexander A. Govyadinov , Viktor A. Podolskiy

Plastic deformation in metallic glasses at room temperature leads to the development of shear bands due to shear localization. In many experiments, shear bands have shown local density variations along their path, with a distinct imbalance…

无序系统与神经网络 · 物理学 2024-07-22 Harald Rösner , Arabinda Bera , Alessio Zaccone

We theoretically investigate dispersion of plasma waves propagating in a lateral plasmonic crystal based on a two-dimensional electron system with grating gates. Two specific configurations are analyzed: a system with single grating gate…

介观与纳米尺度物理 · 物理学 2026-01-27 I. V. Gorbenko , P. A. Gusikhin , V. Yu. Kachorovskii , V. M. Muravev

In this study, we unveil an eccentric superradiance phenomenon in molecular aggregates coupled to surface plasmon polaritons. Through the quantization of electromagnetic fields in media, we demonstrate that superradiance can be…

化学物理 · 物理学 2026-05-21 Yi-Ting Chuang , Liang-Yan Hsu

We study bandstructure properties of periodic optical systems composed of lossy and intrinsically dispersive materials. To this end, we develop an analytical framework based on adjoint modes of a lossy periodic electromagnetic system and…

光学 · 物理学 2018-03-19 Christian Wolff , Kurt Busch , N. Asger Mortensen

Group velocity of electromagnetic waves in plasmas derived by standard relativistic resistive MHD (resistive RMHD) equations is superluminal. If we assume that the group velocity represents the propagation velocity of a signal, we have to…

高能天体物理现象 · 物理学 2015-05-30 Shinji Koide , Ryogo Morino

Steep or near-vertical Floquet dispersion in photonic time crystals (PTCs) is often read as fast, even apparently superluminal, transport. Here, we demonstrate that this anomaly arises from modulation-driven geometric drift, not energy…

光学 · 物理学 2026-02-04 Kyungmin Lee , Younsung Kim , Kun Woo Kim , Bumki Min

Metagrating is a new concept for wavefront manipulation that, unlike phase gradient metasurfaces, does not suffer from low efficiency and also has a less complicated fabrication process. In this paper, a compound metallic grating (a…

光学 · 物理学 2020-06-24 Mahdi Rahmanzadeh , Amin Khavasi

The Generalized Langevin Equation (GLE) is a Stochastic Integro-Differential Equation that is commonly used to describe the velocity of microparticles that move randomly in viscoelastic fluids. Such particles commonly exhibit what is known…

概率论 · 数学 2017-11-03 Scott A McKinley , Hung D Nguyen

We investigate the collective plasmonic modes of metal nano-particles in periodic two-dimensional (2D) arrays within a point-dipole description. As an open system, the full-dynamic dispersion relations of the 2D arrays are obtained through…

光学 · 物理学 2016-07-29 Yu-Rong Zhen , Kin Hung Fung , C. T. Chan

We study the group velocity of light in layer-by-layer chiral photonic crystals composed of dielectrics and metals. Through studying the band structures with an extended-zone scheme that is given by a Fourier analysis, we show the existence…

光学 · 物理学 2016-07-29 Kin Hung Fung , Jeffrey Chi Wai Lee , C. T. Chan

The dynamics of the Local Group and its environment provide a unique challenge to cosmological models. The velocity field within 5h-1 Mpc of the Local Group (LG) is extremely ``cold''. The deviation from a pure Hubble flow, characterized by…

天体物理学 · 物理学 2016-08-30 F. Governato , B. Moore , R. Cen , J. Stadel , G. Lake , T. Quinn

Anomalous dispersion cannot occur in a transparent passive medium where electromagnetic radiation is being absorbed at all frequencies, as pointed out by Landau and Lifshitz. Here we show, both theoretically and experimentally, that…

光学 · 物理学 2009-11-06 A. Dogariu , A. Kuzmich , L. J. Wang

We study the dispersions of plasmonic bands that arise from the coupling of electric quadrupole resonances in three dimensional photonic crystals (PCs) consisting of plasmonic spheres. Through analytical derivation, we show that two…

光学 · 物理学 2014-05-30 Dezhuan Han , Yun Lai , Kin Hung Fung , Zhao-Qing Zhang , C. T. Chan