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We discuss the global scattering response of invisibility cloaks over the entire frequency spectrum, from static to very high frequencies. Based on linearity, causality and energy conservation we show that the total extinction and…

Materials Science · Physics 2013-10-25 Francesco Monticone , Andrea Alu

Cloaking elastic waves has, in contrast to the cloaking of electromagnetic waves, remained a fundamental challenge: the latter successfully uses the invariance of Maxwell's equations, from which the field of transformational optics has…

Materials Science · Physics 2020-11-17 Davide Enrico Quadrelli , Richard Craster , Muamer Kadic , Francesco Braghin

Conformal invisibility devices are only supposed to work within the validity range of geometrical optics. Here we show by numerical simulations and analytical arguments that for certain quantized frequencies they are nearly perfect even in…

Optics · Physics 2015-05-27 Huanyang Chen , Ulf Leonhardt , Tomas Tyc

We introduce "stochastic cloaking," where a region of space is concealed from an ensemble of diffusing particles whose individual trajectories are governed by a stochastic (Langevin) equation. Our simulations reveal how different…

Recently, invisible cloaks have attracted much attention due to their exciting property of invisibility, which are based on a solid theory of transformation optics and quasi-conformal mapping. Two kinds of cloaks have been proposed:…

Optics · Physics 2015-05-14 Hui Feng Ma , Wei Xiang Jiang , Xin Mi Yang , Xiao Yang Zhou , Tie Jun Cui

Invisibility cloaks for flexural waves have been mostly examined in the continuous-wave regime, while invisibility is likely to deteriorate for short pulses. Here, we propose the practical realization of a unidirectional invisibility cloak…

Classical Physics · Physics 2023-08-02 Kun Tang , Eitam Luz , David Amram , Luna Kadysz , Sebastien Guenneau , Patrick Sebbah

By applying the interplay among the nodal points of partial waves, along with the concept of streamline in fluid dynamics for the probability flux, a quantum invisible cloak to the electron transport in a host semiconductor is demonstrated…

Quantum Physics · Physics 2015-06-16 Jeng Yi Lee , Ray-Kuang Lee

Electromagnetic wave behaviour in an anisotropic medium with a two dimensional arbitrary geometry is studied. The aim is to trace the path of a ray in such a complex medium for the purpose of achieving cloaking (invisibility). A coordinate…

Optics · Physics 2015-11-30 H. H. Sidhwa , R. P. Aiyar , S. V. Kulkarni

We propose a scheme of acoustic spherical cloaking by means of background irrotational flow in compressible fluid. The background flow forms a virtual curved spacetime and guides the sound waves bypass the cloaked objects. To satisfy the…

Classical Physics · Physics 2016-08-24 Ruo-Yang Zhang , Qing Zhao , Mo-Lin Ge

We address quantum invisibility in the context of electronics in nanoscale quantum structures. We make use of the freedom of design that quantum corrals provide and show that quantum mechanical objects can be hidden inside the corral, with…

Mesoscale and Nanoscale Physics · Physics 2010-05-18 J. Fransson , H. C. Manoharan , A. V. Balatsky

Ray-tracing exercise and full-wave analysis were performed to validate the performance of a new type of cloak composed of isotropic metamaterials. It is shown that objects inside the folded region of this cloak appear invisible to the…

Optics · Physics 2009-08-25 Yu Luo , Jingjing Zhang , Hongsheng Chen , Bae-Ian Wu , Lixin Ran , Jin Au Kong

The concept of cloaking -- hiding objects from external detection -- has seen wide success in linear systems. Yet, translating these advancements to nonlinear mechanical systems remains an open challenge. Here, we present a new approach to…

A near-perfect, non-singular cylindrical invisibility cloak with diamond cross section is achieved by a two-step coordinate transformation. A small line segment is stretched and then blown up into a diamond space, and finally the cloak…

Optics · Physics 2011-12-21 Wei Li , Jianguo Guan , Zhigang Sun , Wei Wang , Qingjie Zhang

A new type of cloak is discussed: one that gives all cloaked objects the appearance of a flat conducting sheet. It has the advantage that none of the parameters of the cloak is singular and can in fact be made isotropic. It makes broadband…

Optics · Physics 2009-11-13 Jensen Li , J. B. Pendry

An analytical method of electromagnetic wave interactions with a general radially anisotropic cloak is established. It is able to deal with arbitrary parameters ($\epsilon_r(r)$, $\mu_r(r)$, $\epsilon_t(r)$ and $\mu_t(r)$) of a radially…

Optics · Physics 2009-10-02 Cheng-Wei Qiu , Andrey Novitsky , Hua Ma , Shaobo Qu

We employ the analytical results for the spatial transformation of the electromagnetic fields to obtain and analyze explicit expressions for the structure of the electromagnetic fields in invisibility cloaks, beam splitters, and field…

This paper proposes a radial dependent dispersive finite-difference time-domain method for the modelling of electromagnetic cloaking structures. The permittivity and permeability of the cloak are mapped to the Drude dispersion model and…

Classical Physics · Physics 2009-11-13 Yan Zhao , Christos Argyropoulos , Yang Hao

Coordinate-transformation cloaking is based on the design of a metamaterial shell made of an anisotropic, spatially inhomogeneous "transformation medium" that allows rerouting the impinging wave around a given region of space. In its…

Invisibility or unhearability cloaks have been made possible by using metamaterials making light or sound flow around obstacle without the trace of reflections or shadows. Metamaterials are known for being flexible building units that can…

We present a theory for the cloaking of arbitrarily-shaped objects and demonstrate electromagnetic scattering-cancellation through designed homogeneous coatings. First, in the small-particle limit, we expand the dipole moment of a coated…

Mesoscale and Nanoscale Physics · Physics 2014-05-26 Carlo Forestiere , Luca Dal Negro , Giovanni Miano