Topological valley plasmons in twisted monolayer-double graphene moir\'e superlattices

In topological photonics, artificial photonic structures are constructed for realizing nontrivial unidirectional propagation of photonic information. On the other hand, moir\'e superlattices are emerging as an important avenue for engineering quantum materials with novel properties. In this paper, we combine these two aspects and demonstrate theoretically that moir\'e superlattices of small-angle twisted monolayer-bilayer graphene provide a natural platform for valley protected plasmons. Particularly, a complete plasmonic bandgap appears stemming from the distinct optical conductivities of the ABA and ABC stacked triangular domains. Moreover, the plasmonic crystals exhibit nonzero valley Chern numbers and unidirectional transport of plasmonic edge states protected from inter-valley scattering is presented

Optical Extinction Properties of Perforated Gold-Silica-Gold Multilayer Nanoshells

Symmetry breaking in gold nanoshell (or multilayer nanoshells) can supply many interesting optical properties, which has been studied in gold nanostrucutres such as nanocup, nanoegg, and core offset gold-silica-gold multilayer nanoshells. In this work, the optical extinction properties of the perforated gold-silica-gold multilayer nanoshells are studied by the discrete dipole approximation method simulations and plasmon hybridization theory. The extinction spectra of these particles are sensitive to the orientation of the particle with respect to polarization of the light due to the symmetry breaking. Because of the coupling of the plasmon resonance modes between the inner gold sphere and the outer nanocup structure, the perforated gold-silica-gold nanoshell provides the additional plasmon resonance peak and an even greater spectral tunability comparing with the nanocup of similar dimensions. By changing the geometry of the particles, the extinction peaks of the particles can be easily tuned into the near-infrared region, which is favorable for biological applications. The local refractive index sensitivity of the particles is also investigated, and the multiple extinction peaks simultaneous shift is found as surrounding medium is altered. The perforated gold-silica-gold multilayer nanoshells may provide various applications ranging from angularly selective filters to biological sensors

Absorption spectrum of the Nd:KGdP₄O₁₂ crystal at room temperature.

<p>Absorption spectrum of the Nd:KGdP₄O₁₂ crystal at room temperature.</p

Structure projection of Nd:KGdP₄O₁₂ along the [010] direction. (Here, all the oxygen atoms have been omitted.).

<p>Structure projection of Nd:KGdP₄O₁₂ along the [010] direction. (Here, all the oxygen atoms have been omitted.).</p

The crystalline forms {hkl} observed in the Nd:KGdP₄O₁₂ crystal and the corresponding <i>d</i>_hkl arranged by decreasing sense.

<p>The crystalline forms {hkl} observed in the Nd:KGdP₄O₁₂ crystal and the corresponding <i>d</i>_hkl arranged by decreasing sense.</p

The IR and Raman spectra of Nd:KGdP₄O₁₂ at room temperature.

<p>The IR and Raman spectra of Nd:KGdP₄O₁₂ at room temperature.</p

Comparison of spectroscopic properties of the Nd:KGdP₄O₁₂ crystal with other Nd³⁺-doped crystals.

<p>Comparison of spectroscopic properties of the Nd:KGdP₄O₁₂ crystal with other Nd³⁺-doped crystals.</p

The result of chemical analysis for the as-grown crystal of 5 at% Nd³⁺-doped KGdP₄O₁₂.

<p>The result of chemical analysis for the as-grown crystal of 5 at% Nd³⁺-doped KGdP₄O₁₂.</p

Thermal diffusivities and thermal conductivities of the Nd:KGdP₄O₁₂ crystal along the <i>c</i>* direction.

<p>Thermal diffusivities and thermal conductivities of the Nd:KGdP₄O₁₂ crystal along the <i>c</i>* direction.</p

U73122 completely blocks NEM or SNP-induced SOCE and inhibits PMA-elicited spreading of neutrophils.

<p>(A) representative tracings of [Ca²⁺]_c elevation induced by NEM (100 µM) in the presence or absence of U73122 (10 µM) in Ca²⁺-containing buffer. (B) Statistic results are means ± S.E.M (n = 30 from three independent experiments).^*<i>P</i><0.01, compared with NEM.^#<i>P</i><0.01, compared with SNP. (C) PMA-activated and adherent neutrophils image was obtained by DIC. (D) The effect of U73122 (10 µM) on morphology of PMA-activated neutrophils.</p