We report a pitch invariance in cholesteric liquid crystals (CLCs) independent of temperature by mixing two chiral dopants. One dopant tends to shorten the helical pitch of the CLC, but the other makes the pitch longer, with increasing temperatures. From an analysis of temperature dependencies of the pitch for each dopant, we determined the mixing ratio of two chiral dopants for the pitch invar...

We discuss the importance of distributed amplification for high-speed soliton communication systems through numerical simulations by considering the distributed gain provided by stimulated Raman scattering or erbium dopants. Hybrid amplification schemes are also considered. At a bit rate of 40 Gb/s, the use of distributed amplification is found to improve the transmission distance (deduced from...

We present first results of the analysis of molecular beam epitaxy-grown Be:GaAs delta-doped layers with atomic resolution. These were obtained using cross-sectional scanning tunneling microscopy. At low Be areal density, the width of the delta layers is 1 nm, whereas at higher Be areal densities the spread of the layers is appreciable and the widths are approximately 5 nm. This spreading is mo...

The highest-temperature superconductors are electronically inhomogeneous at the nanoscale, suggesting the existence of a local variable that could be harnessed to enhance the superconducting pairing. Here we report the relationship between local doping and local strain in the cuprate superconductor Bi(2)Sr(2)CaCu(2)O(8+x). We use scanning tunneling microscopy to discover that the crucial oxygen...

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Giant polarization rotation in a ZnO single crystal was experimentally demonstrated based on a novel phenomenon occurring at the nanometric scale. The ZnO crystal was doped with N(+) and N(2+) ions serving as p-type dopants. By applying an in-plane current using a unique arrangement of electrodes on the device, current-induced polarization rotation of the incident light was observed. From the r...

In this work we aim at understanding the effect of n- and p-type substitutional doping in the case of matrix-embedded and freestanding Si nanocrystals. By means of ab initio calculations we identify the preferential positioning of the dopants and its effect on the structural properties with respect to the undoped case. Subsequently, we consider the case of phosphorus and boron co-doped nanocrys...

Lithium (Li) dopants have garnered attention as a means to enhance hydrogen (H 2 ) binding energies and capacities in 2D boron-based materials. However, it is unclear if how these affect H dissociation chemisorption. Using density functional theory (DFT) nudged elastic band (NEB) calculations, reaction pathways for on borophene-hydride striped-borophene are investigated the presence of Li dopan...