Category Physics

Multilayer fishnet metamaterial. (a) Sketch of the structure. Thicknesses of MgF2 and Au layers are 45 and 30 nm, respectively. Thickness of Si3N4 membrane is 50 nm. Lattice period is 750 × 750 nm. Size of holes is 260 × 530 nm. (b) Experimentally measured transmission spectrum of the fishnet metamaterial. Inset shows a scanning electron microscopy image of the fabricated structure. (c) Effective refractive index of the fishnet metamaterial extracted for the normal incidence. The marked lines in b and c represent the wavelengths in the regions of elliptic dispersion (red), crossover optical topological transition (green) and hyperbolic dispersion (blue).

Physicists have discovered radical new properties in a nanomaterial which opens new possibilities for highly efficient thermophotovolta...

Plan of the SuperKEKB accelerator with the Belle-II detector. Credit: ill./©: KEK

The SuperKEKB particle accelerator at KEK research center in Japan has recently reached a major milestone: electrons and positrons have been circulated for the first time around the rings. The accelerator is now being commissioned and the start of data taking is foreseen for 2017. One of the core questions to be investigated in these experiments is why the universe today is filled almost only with matter while in the Big Bang matter and antimatter should have been created in equal amounts.

The group of Professor Concettina Sfienti at the Institute of Nuclear Physics at Mainz University will be working together with some 600 scientists from 23 countries to analyze the data.

As the new accelerator is designed ...

Layout of the NH3 synthesis device bearing the Nb-SrTiO3 photoelectrode loaded with Au-NPs and a Zr/ZrOx thin film Credit: Copyright Hokkaido University

By using a photoelectrode in which gold nanoparticles are loaded on an oxide semiconductor substrate, a research has worked to develop a method of artificial photosynthesis that may prove to be an excellent light energy conversion system.

– Ammonia has gained attention as a next-generation energy carrier. By combining an optical antenna structure that can concentrate light into a nano-space, and a co-catalyst that selectively adsorbs nitrogen, we have succeeded in selectively synthesizing ammonia from water and di-nitrogen under visible light irradiation...

As-grown (Er,Yb):GdAl3(BO3)4 crystal by using high-temperature solution growth on dipped seeds (a) . Credit: Nikolay Leonyuk

It can be used in medicine, communications systems and also in research. ‘In collaboration with our colleagues of the Center for Optical Materials and Technologies, Belarusian National Technical University, we have developed a highly efficient diode-pumped eye-safe laser, which can be used in ophthalmology, communication systems and ranging’, says Prof Nikolay Leonyuk, The development of such laser became possible to the fact that the team of scientists had created a laboratory growth technology of single crystals with desired properties.

The emission with wavelengths 1500 – 1600 nm is agreeably safe for the eyes and seems prospective for practical applications in me...