This method is expected to greatly facilitate the presently available wearable gadgets in HR computation during various physical activities.

An optical metamaterial is capable of manipulating light in nanometer scale that goes beyond what is possible with conventional materials. Taking advantage of this special property, metamaterial-assisted illumination nanoscopy (MAIN) possesses tremendous potential to extend the resolution far beyond conventional structured illumination microscopy. Among the available MAIN designs, hyperstructured illumination that utilizes strong dispersion of a hyperbolic metamaterial (HMM) is one of the most promising and practical approaches, but it is only theoretically studied. In this paper, we experimentally demonstrate the concept of hyperstructured illumination. A ∼80 nm resolution has been achieved in a well-known Ag/SiO2 multilayer HMM system by using a low numerical aperture objective (NA = 0.5), representing a 6-fold resolution enhancement of the diffraction limit. The resolution can be significantly improved by further material optimization.

Graphene-metal interfaces have recently become popular for graphene growth and for making contacts in numerous thermal and photo-electronic devices. A number of studies have already been made to investigate the interfacial properties when single layer graphene is grown on metal substrates. In this study, we consider the physisorption of bilayer graphene on metals and find a significant bandgap opening which is otherwise absent in the single layer case. This gap arises from the asymmetry in the bilayer due to the charge transfer process at the interface. This charge transfer also causes doping in the bilayer graphene and a corresponding shift in the Fermi level. In this work, we present a thorough investigation into the induced bandgap and Fermi level shift when bilayer graphene is adsorbed on Cu, Al, Ag, Pt, and Au(111) surfaces first by reporting their values from Density Functional Theory (DFT) studies with Local Density Approximation functional used for exchange-correlation energy. Next, to obtain an enhanced picture of the surface physics at play (which is usually obscured by the complexities of DFT), we provide an analytical model to relate the induced bandgap and Fermi level shift to the metal work function and interface separation distance. The values predicted from the model shows a high degree of correlation with the values obtained from the DFT simulation. The results are expected to greatly facilitate the understanding of bilayer graphene adsorption on metals, which in turn may aid the study of graphene electronic devices.

We show that thermal radiation from a topological insulator carries a nonzero average spin angular momentum.

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