Author
John B. Pendry
Other affiliations: University of California, San Diego, Duke University, Bell Labs ...read more
Bio: John B. Pendry is an academic researcher from Imperial College London. The author has contributed to research in topics: Metamaterial & Plasmon. The author has an hindex of 100, co-authored 536 publications receiving 88802 citations. Previous affiliations of John B. Pendry include University of California, San Diego & Duke University.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a random medium in which scattering is exclusively in the forward direction is considered and the Fourier components of the intensity are shown to propagate independently, at small wavevectors the intensity propagates very simply through increasing thickness, z, of medium, as λ z, and Fourier component of the object can easily be reconstructed.
Abstract: We consider a random medium in which scattering is exclusively in the forward direction. Waves are emitted by an object in the medium and Fourier components of the intensity are shown to propagate independently. At small wavevectors the intensity propagates very simply through increasing thickness, z, of medium, as λ z , and Fourier components of the object can easily be reconstructed. For wavevectors greater than a critical value, q c , the intensity changes with z in a more complex fashion making it very difficult to reconstruct the object. They develop a simple model for the singularity and apply it to the reconstruction of an object degraded by passage through a random medium.
1 citations
TL;DR: Ma et al. as mentioned in this paper developed a theory of an optical response of nanoparticles adsorbed on the surface of stacked nanosheet hyperbolic substrates, which could be later verified experimentally.
Abstract: Experimental studies of have been recently performed to determine the optical effect of adsorption of arrays of gold nanoparticles, NPs (16 nm or 40 nm in diameter) on reflective substrates (Ma et al., ACS Photonics, 2018, 5, 4604-4616; Ma et al., ACS Nano, 2020, 14, 328-336) and on transparent interfaces (Montelongo et al., Nat. Mater., 2017, 16, 1127-1135). As predicted by the theory (Sikdar et al., Phys. Chem. Chem. Phys., 2016, 18, 20486-20498), a reflection quenching effect was observed on the reflective substrates, in the frequency domain centred around the nanoparticle localised plasmon resonance. Those results showed a broad dip in reflectivity, which was deepening and red-shifting with increasing array densities. In contrast, the second system has shown, also in accordance with the theory (Sikdar and Kornyshev, Sci. Rep., 2016, 6, 1-16), a broad reflectivity peak in the same frequency domain, increasing in intensity and shifting to the red with densification of the array. In the present paper, we develop a theory of an optical response of NP arrays adsorbed on the surface of stacked nanosheet hyperbolic substrates. The response varies between quenched and enhanced reflectivity, depending on the volume fractions of the metallic and dielectric components in the hyperbolic metamaterial. We reproduce the results of the earlier works in the two opposite limiting cases - of a pure metal and a pure dielectric substrates, while predicting novel resonances for intermediate compositions. Whereas the metal/dielectric ratio in the hyperbolic substrate cannot be changed in time - for each experiment a new substrate should be fabricated - the density of the adsorbed nanoparticle arrays can be controlled in real time in electrochemical photonic cells (Montelongo et al., Nat. Mater., 2017, 16, 1127-1135; Ma et al., ACS Photonics, 2018, 5, 4604-4616; Ma et al., ACS Nano, 2020, 14, 328-336). Therefore, we systematically study the effect of the array density on the optical response of such systems, which could be later verified experimentally. We also investigate the manifestation of these findings in a hyperbolic-Fabry-Perot cell.
1 citations
TL;DR: It is found that surface corrugation always leads to a decrease in the zero-point energy of a metallic surface, but the decrease is not strong enough to drive a surface reconstruction on its own.
Abstract: Surface distortion splits surface plasmons asymmetrically in energy with a net lowering of zero-point energy. We contrast this with the symmetrical distortion of electronic energy levels. We use conformal mapping to demonstrate this splitting and find that surface corrugation always leads to a decrease in the zero-point energy of a metallic surface, but the decrease is not strong enough to drive a surface reconstruction on its own. A second metallic surface in proximity to the first gives a more significant lowering of energy, sufficient to drive the instability of a mercury thin film. This mechanism provides a fundamental length scale limit to planar nanostructures.
1 citations
TL;DR: In this paper, the authors present calculations of the X-ray absorption spectra and diffuse LEED intensity patterns to illustrate the extraction of local structural parameters for atomic and molecular adsorbates on clean surfaces.
1 citations
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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
TL;DR: By altering the structure of a metal's surface, the properties of surface plasmons—in particular their interaction with light—can be tailored, which could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved.
Abstract: Surface plasmons are waves that propagate along the surface of a conductor. By altering the structure of a metal's surface, the properties of surface plasmons--in particular their interaction with light--can be tailored, which offers the potential for developing new types of photonic device. This could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics.
10,689 citations
TL;DR: These experiments directly confirm the predictions of Maxwell's equations that n is given by the negative square root ofɛ·μ for the frequencies where both the permittivity and the permeability are negative.
Abstract: We present experimental scattering data at microwave frequencies on a structured metamaterial that exhibits a frequency band where the effective index of refraction (n) is negative. The material consists of a two-dimensional array of repeated unit cells of copper strips and split ring resonators on interlocking strips of standard circuit board material. By measuring the scattering angle of the transmitted beam through a prism fabricated from this material, we determine the effective n, appropriate to Snell's law. These experiments directly confirm the predictions of Maxwell's equations that n is given by the negative square root of epsilon.mu for the frequencies where both the permittivity (epsilon) and the permeability (mu) are negative. Configurations of geometrical optical designs are now possible that could not be realized by positive index materials.
8,477 citations
TL;DR: In this paper, it was shown that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu/sub eff/, which can be tuned to values not accessible in naturally occurring materials.
Abstract: We show that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu//sub eff/, which can be tuned to values not accessible in naturally occurring materials, including large imaginary components of /spl mu//sub eff/. The microstructure is on a scale much less than the wavelength of radiation, is not resolved by incident microwaves, and uses a very low density of metal so that structures can be extremely lightweight. Most of the structures are resonant due to internal capacitance and inductance, and resonant enhancement combined with compression of electrical energy into a very small volume greatly enhances the energy density at critical locations in the structure, easily by factors of a million and possibly by much more. Weakly nonlinear materials placed at these critical locations will show greatly enhanced effects raising the possibility of manufacturing active structures whose properties can be switched at will between many states.
8,135 citations
TL;DR: Recent advances at the intersection of plasmonics and photovoltaics are surveyed and an outlook on the future of solar cells based on these principles is offered.
Abstract: The emerging field of plasmonics has yielded methods for guiding and localizing light at the nanoscale, well below the scale of the wavelength of light in free space. Now plasmonics researchers are turning their attention to photovoltaics, where design approaches based on plasmonics can be used to improve absorption in photovoltaic devices, permitting a considerable reduction in the physical thickness of solar photovoltaic absorber layers, and yielding new options for solar-cell design. In this review, we survey recent advances at the intersection of plasmonics and photovoltaics and offer an outlook on the future of solar cells based on these principles.
8,028 citations