Ideas from the Metamaterials Community
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Tailoring and imaging the plasmonic local density of states in crystalline nanoprisms by Sviatlana Viarbitskaya, Alexandre Teulle, Renaud Marty, Jadab Sharma, Christian Girard, Arnaud Arbouet & Erik Dujardin in Nature Posted: Apr 29, 2013 |
The collective oscillation of electrons in metallic nanoparticles, called plasmons, generate high local fields which can be used to enhance nonlinear effects, or even generate lasing in spasers. Those processes strongly depend on the distribution of the electric field, or local density of state (LDOS). The LDOS can be predicted by theory or simulations, but it is difficult to measure directly. In this recent article published in Nature Materials, Viarbitskaya et al. present a clever technique, based on two-photon luminescence, to experimentally determine the LDOS. |
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Fabrication of an Inductively Coupled Plasma Antenna in Low Temperature Co-Fired Ceramic by J. Taff, M. Yates, C. Lee, S. Shawver, J. Browning, D. Plumlee in Int. J. Appl. Ceram. Technol Posted: Apr 26, 2013 |
The group at Boise State is developing a technology for high-power spiral RF antennas embedded in durable ceramic substrates. While the current target application is inductively coupled plasmas, the technique shows promise for high-power RF magnetic metamaterials. |
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Overcoming Mutual Blockage Between Neighboring Dipole Antennas Using a Low-Profile Patterned Metasurface by Monti, A. in IEEE Antennas and Wireless Prop. Lett. vol. 11, p. 1414, 2012 Posted: Jan 16, 2013 |
Monti et al. prove that metallic metasurfaces can serve as efficient near-field cloaks that reduce mutual blockage of electrically close antennas. The approach is described as originating from "mantle cloaking" concept (A. Alu, PRB 80, 2009). Cloaking with ultrathin, nearly lossless layers is an attractive idea both for near- and far-field applications. |
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Observation of quantum tunneling between two plasmonic nanoparticles by Jonathan Scholl, Aitzol Garcia-Etxarri, Ai Leen Koh, and Jennifer A Dionne in Nano Lett. 2012 Posted: Jan 16, 2013 |
In a classical electrodynamics, the strength of plasmon resonances of two closely spaced metallic particles increases as the particle gap size decreases. In contrast, quantum mechanics predicts that electron tunneling will strongly diminish the dimer plasmon strength for subnanometer separations. Scholl et al. directly observe the plasmon resonances of coupled metallic nanoparticles as their separation is reduced to atomic sizes. |
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Perfect invisibility cloaking by isotropic media by T. Xu, Y. C. Liu, Y. Zhang, C. K. Ong, and Y. G. Ma in Physical Review A, 2012 Posted: Jan 16, 2013 |
Feasibility of cloaking with isotropic, non-magnetic media, first suggested by Leonhardt in 2006, is a practically important question in theoretical and applied optics. In this paper, Xu et al. show that adding negative magnetic permeability (and negative permittivity) to conformal mapping scenarios leads to accurate eikonal-limit cloaking in the limit of zero loss. |
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"Large fluorescence enhancements of fluorophore ensembles with multilayer plasmonic substrates: Comparison of theory and experim by Henryk Szmacinski *, Ramachandram Badugu , Farhad Mahdavi , Steve Blair , and Joseph R. Lakowicz in Journal of Physical Chemistry Posted: Jan 16, 2013 |
Fluorescence enhancement is an oftentimes confusing subject. In this work, the authors perform a relatively clean experiment, with fluorophores deposited above a silver mirror and a layer of silver nanoparticles. The origin of the fluorescence enhancement is explained, and nice agreement found with theory. |
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Recent advances in transformation optics by Yongmin Liu and Xiang Zhang in Nanoscale 4 Posted: Jan 16, 2013 |
Liu and Zhang provide us with a fairly comprehensive review of the still burgeoning field of transformation optics and potential devices that might be enabled by the emerging powerful design techniques. |
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On the practicability of pentamode mechanical metamaterials by M. Kadic, T. Buckmann, N. Stenger, M. Thiel and M. Wegener in Applied Physics Letters, 2012 Posted: Oct 1, 2012 |
A recent paper from Karlsruhe University reports the first-of-a-kind mechanical metamaterial with properties useful for transformation acoustics - a pentamode medium. The new material has a complicated three-dimensional microstructure, which is sculpted with an impressive quality using a novel dip-in direct laser writing technique. The old saying goes "a chain is only as strong as its weakest link", and in accord with this principle, the new metamaterial makes use of ultrathin beam junctions to drastically reduce its shear modulus. |
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Artificial Faraday rotation using a ring metamaterial structure without static magnetic field by Toshiro Kodera, Dimitrios L. Sounas, and Christophe Caloz in Applied Physical Letters Posted: Jul 30, 2012 |
Kodera et. al. demonstrate Faraday rotation in artificial, non-magnetic composites, by inducing gyrotropic-like precession in transistor-loaded split-ring resonators. This is an instructive step towards probing a wide array of magnetic phenomena in non-magnetic composites, beyond just the simple linear magnetic permeability |
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Electromagnetic forces on a discrete spherical invisibility cloak under time-harmonic illumination by P.C. Chaumet et al. in Phys. Rev. Lett. Posted: Jun 25, 2012 |
A French-Australian collaboration studies electromagnetic forces and torque on an object protected by a spherical invisibility cloak.They find that even an imperfect discrete cloak can reduce the radiation pressure significantly. |