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Electromagnetic detection of a perfect carpet cloak.

Shi X, Gao F, Lin X, Zhang B - Sci Rep (2015)

Bottom Line: It has been shown that a spherical invisibility cloak originally proposed by Pendry et al. can be electromagnetically detected by shooting a charged particle through it, whose underlying mechanism stems from the asymmetry of transformation optics applied to motions of photons and charges [PRL 103, 243901 (2009)].However, the conceptual three-dimensional invisibility cloak that exactly follows specifications of transformation optics is formidably difficult to implement, while the simplified cylindrical cloak that has been experimentally realized is inherently visible.On the other hand, the recent carpet cloak model has acquired remarkable experimental development, including a recently demonstrated full-parameter carpet cloak without any approximation in the required constitutive parameters.

View Article: PubMed Central - PubMed

Affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.

ABSTRACT
It has been shown that a spherical invisibility cloak originally proposed by Pendry et al. can be electromagnetically detected by shooting a charged particle through it, whose underlying mechanism stems from the asymmetry of transformation optics applied to motions of photons and charges [PRL 103, 243901 (2009)]. However, the conceptual three-dimensional invisibility cloak that exactly follows specifications of transformation optics is formidably difficult to implement, while the simplified cylindrical cloak that has been experimentally realized is inherently visible. On the other hand, the recent carpet cloak model has acquired remarkable experimental development, including a recently demonstrated full-parameter carpet cloak without any approximation in the required constitutive parameters. In this paper, we numerically investigate the electromagnetic radiation from a charged particle passing through a perfect carpet cloak and propose an experimentally verifiable model to demonstrate symmetry breaking of transformation optics.

No MeSH data available.


Related in: MedlinePlus

The designed carpet cloak with a layered structure and the scattering field excited by the spectral component of the current passing through it. (a) A plane electromagnetic wave with frequency 1 GHz passes the carpet cloak designed with Zn-Ni-Fe composite (blue) and air (white) in the surrounding background of Teflon. (b) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1 GHz and phase velocity . (c) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1GHz and phase velocity .
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f4: The designed carpet cloak with a layered structure and the scattering field excited by the spectral component of the current passing through it. (a) A plane electromagnetic wave with frequency 1 GHz passes the carpet cloak designed with Zn-Ni-Fe composite (blue) and air (white) in the surrounding background of Teflon. (b) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1 GHz and phase velocity . (c) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1GHz and phase velocity .

Mentions: To verify the results analyzed above, we propose a full-parameter carpet cloak that is implementable in reality. To facilitate observation, the radiation from the charged particle can be simulated in a microwave experiment by monitoring only one spectral component. It can be seen from equation (2) that the carpet cloak requires magnetism. Because of the 2D nature under consideration, we only need to construct three constitutive parameters: and . Simply using a layered metamaterial structure of homogeneous and isotropic materials, we design the carpet cloak as shown in Fig. 4a. The two materials that constitute the cloak are air with and and Zn-Ni-Fe composite with and 16 in the surrounding background Teflon with and . The thickness of air and the composite are and respectively. In the u-v-z orthogonal coordinates (u-axis and v-axis in the x-y plane; u-axis perpendicular to layers), the effective parameters are and . The angle between layers and the horizontal plane is . The left and right parts of the cloak can thus been constructed in a symmetric fashion. We simulate a plane wave at 1GHz with magnetic field perpendicular to the x-y plane going through the carpet cloak that is composed of realistic metamaterials as shown in Fig. 4a. The pattern on the right gets a little dim because of the loss from the carpet cloak.


Electromagnetic detection of a perfect carpet cloak.

Shi X, Gao F, Lin X, Zhang B - Sci Rep (2015)

The designed carpet cloak with a layered structure and the scattering field excited by the spectral component of the current passing through it. (a) A plane electromagnetic wave with frequency 1 GHz passes the carpet cloak designed with Zn-Ni-Fe composite (blue) and air (white) in the surrounding background of Teflon. (b) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1 GHz and phase velocity . (c) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1GHz and phase velocity .
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4441199&req=5

f4: The designed carpet cloak with a layered structure and the scattering field excited by the spectral component of the current passing through it. (a) A plane electromagnetic wave with frequency 1 GHz passes the carpet cloak designed with Zn-Ni-Fe composite (blue) and air (white) in the surrounding background of Teflon. (b) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1 GHz and phase velocity . (c) The angular distribution of the scattering field along a semicircle far from the cloak excited by the current with frequency 1GHz and phase velocity .
Mentions: To verify the results analyzed above, we propose a full-parameter carpet cloak that is implementable in reality. To facilitate observation, the radiation from the charged particle can be simulated in a microwave experiment by monitoring only one spectral component. It can be seen from equation (2) that the carpet cloak requires magnetism. Because of the 2D nature under consideration, we only need to construct three constitutive parameters: and . Simply using a layered metamaterial structure of homogeneous and isotropic materials, we design the carpet cloak as shown in Fig. 4a. The two materials that constitute the cloak are air with and and Zn-Ni-Fe composite with and 16 in the surrounding background Teflon with and . The thickness of air and the composite are and respectively. In the u-v-z orthogonal coordinates (u-axis and v-axis in the x-y plane; u-axis perpendicular to layers), the effective parameters are and . The angle between layers and the horizontal plane is . The left and right parts of the cloak can thus been constructed in a symmetric fashion. We simulate a plane wave at 1GHz with magnetic field perpendicular to the x-y plane going through the carpet cloak that is composed of realistic metamaterials as shown in Fig. 4a. The pattern on the right gets a little dim because of the loss from the carpet cloak.

Bottom Line: It has been shown that a spherical invisibility cloak originally proposed by Pendry et al. can be electromagnetically detected by shooting a charged particle through it, whose underlying mechanism stems from the asymmetry of transformation optics applied to motions of photons and charges [PRL 103, 243901 (2009)].However, the conceptual three-dimensional invisibility cloak that exactly follows specifications of transformation optics is formidably difficult to implement, while the simplified cylindrical cloak that has been experimentally realized is inherently visible.On the other hand, the recent carpet cloak model has acquired remarkable experimental development, including a recently demonstrated full-parameter carpet cloak without any approximation in the required constitutive parameters.

View Article: PubMed Central - PubMed

Affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.

ABSTRACT
It has been shown that a spherical invisibility cloak originally proposed by Pendry et al. can be electromagnetically detected by shooting a charged particle through it, whose underlying mechanism stems from the asymmetry of transformation optics applied to motions of photons and charges [PRL 103, 243901 (2009)]. However, the conceptual three-dimensional invisibility cloak that exactly follows specifications of transformation optics is formidably difficult to implement, while the simplified cylindrical cloak that has been experimentally realized is inherently visible. On the other hand, the recent carpet cloak model has acquired remarkable experimental development, including a recently demonstrated full-parameter carpet cloak without any approximation in the required constitutive parameters. In this paper, we numerically investigate the electromagnetic radiation from a charged particle passing through a perfect carpet cloak and propose an experimentally verifiable model to demonstrate symmetry breaking of transformation optics.

No MeSH data available.


Related in: MedlinePlus