1,676 research outputs found
Extending the Propagation Distance of a Silver Nanowire Plasmonic Waveguide with a Dielectric Multilayer Substrate
Chemical synthesized silver nanowires have been proved to be the efficient
architecture for Plasmonic waveguides, but the high propagation loss prevents
their widely applications. Here, we demonstrate that the propagation distance
of the plasmons along the Ag NW can be extended if the Ag NW was placed on a
dielectric multilayer substrate containing a photonic band gap, but not placed
on a commonly used glass substrate. The propagation distance at 630 nm
wavelength can reach 16 um even that the Ag NW is as thin as 90 nm in diameter.
Experimental and simulation results further show that the polarization of this
propagating plasmon mode was nearly parallel to the surface of the dielectric
multilayer, so it was excited by a transverse-electric polarized Bloch surface
wave propagating along a polymer nanowire with diameter at only about 170 nm on
the same dielectric multilayer. Numerical simulations were also carried out and
consistent with the experiment results. Our work provides a platform to extend
the propagation distance of plasmonic waveguide and also for the integration
between photonic and plasmonic waveguides on the nanometre scale.Comment: 5 pages, 4 figure
Movable Fiber-Integrated Hybrid Plasmonic Waveguide on Metal Film
A waveguide structure consisting of a tapered nanofiber on a metal film is
proposed and analyzed to support highly localized hybrid plasmonic modes. The
hybrid plasmonic mode can be efficiently excited through the in-line tapered
fiber based on adiabatic conversion and collected by the same fiber, which is
very convenient in the experiment. Due to the ultrasmall mode area of plasmonic
mode, the local electromagnetic field is greatly enhanced in this movable
waveguide, which is potential for enhanced coherence light emitter
interactions, such as waveguide quantum electrodynamics, single emitter
spectrum and nonlinear optics
Tunable boson-assisted finite-range interaction and engineering Majorana corner modes in optical lattices
Nonlocal interaction between ultracold atoms trapped in optical lattices can
give rise to interesting quantum many-body phenomena. However, its realization
usually demands unconventional techniques, for example the artificial gauge
fields or higher-orbit Feshbach resonances, and is not highly controllable.
Here, we propose a valid and feasible scheme for realizing a tunable
finite-range interaction for spinless fermions immersed into the bath of
bosons. The strength of the effective interaction for the fermionic subsystem
is artificially tunable by manipulating bosons, ranging from the repulsive to
attractive regime. And the interaction distance is locked to the hopping of
bosons, making the finite-range interaction perfectly clean for the fermionic
subsystem. Specifically we find that, by introducing an additional staggered
hopping of bosons, the proposal is readily applied to search the Majorana
corner modes in such a spinless system, without implementation of complex
artificial gauge fields, which is totally distinct from existing results
reported in spinful systems. Therefore this scheme provides a potential
platform for exploring the unconventional topological superfluids and other
nontrivial phases induced by long-range interactions in ultracold atoms.Comment: 11 pages, 6 figure
Dietary Bile Salt Types Influence the Composition of Biliary Bile Acids and Gut Microbiota in Grass Carp
Lipid metabolism can influence host’s health. There is increasing evidence for interplay between two key regulating factors in lipid metabolism: bile acids (BAs) and gut microbiota. However, very little is known about how types of different diet-supplemented bile salts (BS) influence this interaction in vivo. We sought to explore these relationships using grass carp (Ctenopharyngodon idellus), which often suffers functional disorder of liver and gallbladder. We studied fluctuations of BAs in the gall and changes of microbial communities in the gut in response to seven different diets: five different BS, chelating BS agent, and control. The BS comprised two primary BS [sodium taurochololate (TCAS) and sodium taurochenodeoxycholate (TCDCAS)], sodium tauroursodeoxycholate (TUDCAS), and two secondary BS [sodium taurodeoxycholate (TDCAS) and sodium taurolithocholate (TLCAS)]. Supplementation of primary BS caused a more significant fluctuation of biliary BAs than secondary BS, and TCAS caused a more prominent increase than TCDCAS and TUDCAS. For the gut microbiota, primary BS tended to increase their diversity and induce community succession, secondary BS resulted in a higher firmicutes/bacteroidetes ratio, while TUDCAS had no significant effects. Changes of the gut microbiota triggered by different types of BS caused alteration in BAs biotransformation. Two-obesity-associated families, Lachnospiraceae and Ruminococcaceae were positively correlated with biliary cholic acid (CA), taurochenodeoxycholic acid (TCDCA), and deoxycholic acid (DCA). As both primary and secondary BS resulted in increased synthesis of toxic secondary Bas by the gut microbiota, future studies should pay closer attention to gut microbiota when considering BA treatment
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