Circular Dichroism Metamirrors with Near-Perfect Extinction

In nature, the beetle <i>Chrysina gloriosa</i> derives its iridescence by selectively reflecting left-handed circularly polarized light only. Here, an optical analogue is suggested based on an ultrathin metamaterial, which is termed circular dichroism metamirror. A general method to design the circular dichroism metasmirror is presented under the framework of Jones calculus. It is analytically shown that the building block of such a metamirror needs to simultaneously break the <i>n</i>-fold rotational (<i>n</i> > 2) symmetry and mirror symmetry. By combining two layers of anisotropic metamaterial structures, a circular dichroism metamirror is designed in the mid-infrared region, which shows perfect reflectance for left-handed circularly polarized light without reversing its handedness, while it almost completely absorbs right-handed circularly polarized light. These findings offer a new methodology to implement novel photonic devices for a variety of applications, including polarimetric imaging, molecular spectroscopy, and quantum information processing

Radiative Anti-Parity-Time Plasmonics_Datasets

This file contains the datasets presented in the paper titled "Radiative Anti-Parity-Time Plasmonics".</p

Dipole-matter interactions governed by the asymmetry of Maxwell equations

Directionally molding the near-field and far-field radiation lies at the heart of nanophotonics and is crucial for applications such as on-chip information processing and chiral quantum networks. The most fundamental model for radiating structures is a dipolar source located inside a homogeneous matter. However, the influence of matter on the directionality of dipolar radiation is oftentimes overlooked, especially for the near-field radiation. We show that the dipole-matter interaction is intrinsically asymmetric and does not fulfill the duality principle, originating from the inherent asymmetry of Maxwell equations, i.e., electric charge and current are ubiquitous but their magnetic counterparts are non-existent to elusive. Moreover, we find that the asymmetric dipole-matter interaction could offer an enticing route to reshape the directionality of not only the near-field radiation but also the far-field radiation. As an example, both the near-field and far-field radiation directionality of Huygens dipole (located close to a dielectric-metal interface) would be reversed, if the dipolar position is changed from the dielectric region to the metal region

Triboelectrification-Induced Large Electric Power Generation from a Single Moving Droplet on Graphene/Polytetrafluoroethylene

Recently, several reports have demonstrated that a moving droplet of seawater or ionic solution over monolayer graphene produces an electric power of about 19 nW, and this has been suggested to be a result of the pseudocapacitive effect between graphene and the liquid droplet. Here, we show that the change in the triboelectrification-induced pseudocapacitance between the water droplet and monolayer graphene on polytetrafluoroethylene (PTFE) results in a large power output of about 1.9 μW, which is about 100 times larger than that presented in previous research. During the graphene transfer process, a very strong negative triboelectric potential is generated on the surface of the PTFE. Positive and negative charge accumulation, respectively, occurs on the bottom and the top surfaces of graphene due to the triboelectric potential, and the negative charges that accumulate on the top surface of graphene are driven forward by the moving droplet, charging and discharging at the front and rear of the droplet

Quasi-Two-Dimensional SiC and SiC₂: Interaction of Silicon and Carbon at Atomic Thin Lattice Plane

The band gap of graphene is nearly zero, and thus novel two-dimensional (2D) semiconductor and band gap engineering of graphene is highly desired for advanced optoelectronic applications. Herein, we have experimentally produced quasi-two-dimensional (quasi-2D) SiC by reaction between graphene and a silicon source, which was designed and supported by Born–Oppenheimer molecular dynamics simulations. The lateral length of the as-synthesized quasi-2D SiC is mainly in the range of 0.3–5 μm while the thickness is commonly below 10 nm. Quasi-2D SiC₂ is also found as a byproduct, which is stable over 3 months in air atmosphere. The exciton binding energy of quasi-2D multilayers SiC can reach 0.23 eV while the band gap is around 3.72 eV. Additionally, in situ transmission electron microscopy has firmly proven that quasi-2D SiC can be synthesized through the reaction between graphene and silicon quantum dots. The first production of quasi-2D SiC and SiC₂ makes the band gap engineering in the graphene lattice plane possible

Triboelectrification-Induced Large Electric Power Generation from a Single Moving Droplet on Graphene/Polytetrafluoroethylene

Recently, several reports have demonstrated that a moving droplet of seawater or ionic solution over monolayer graphene produces an electric power of about 19 nW, and this has been suggested to be a result of the pseudocapacitive effect between graphene and the liquid droplet. Here, we show that the change in the triboelectrification-induced pseudocapacitance between the water droplet and monolayer graphene on polytetrafluoroethylene (PTFE) results in a large power output of about 1.9 μW, which is about 100 times larger than that presented in previous research. During the graphene transfer process, a very strong negative triboelectric potential is generated on the surface of the PTFE. Positive and negative charge accumulation, respectively, occurs on the bottom and the top surfaces of graphene due to the triboelectric potential, and the negative charges that accumulate on the top surface of graphene are driven forward by the moving droplet, charging and discharging at the front and rear of the droplet

Triboelectrification-Induced Large Electric Power Generation from a Single Moving Droplet on Graphene/Polytetrafluoroethylene

Recently, several reports have demonstrated that a moving droplet of seawater or ionic solution over monolayer graphene produces an electric power of about 19 nW, and this has been suggested to be a result of the pseudocapacitive effect between graphene and the liquid droplet. Here, we show that the change in the triboelectrification-induced pseudocapacitance between the water droplet and monolayer graphene on polytetrafluoroethylene (PTFE) results in a large power output of about 1.9 μW, which is about 100 times larger than that presented in previous research. During the graphene transfer process, a very strong negative triboelectric potential is generated on the surface of the PTFE. Positive and negative charge accumulation, respectively, occurs on the bottom and the top surfaces of graphene due to the triboelectric potential, and the negative charges that accumulate on the top surface of graphene are driven forward by the moving droplet, charging and discharging at the front and rear of the droplet

Summary of variants.

<p>Summary of variants.</p

The proximal region (positions -56 bp to -50 bp) of the <i>TYR</i> promoter was required for LEF-1-mediated gene expression of the <i>TYR</i> promoter.

<p><b>A, B</b> Transcriptional activity of LEF-1 on various <i>TYR</i> deleted or mutated promoters (<i>TYR5</i>) by luciferase assay. UACC903 cells were transiently transfected with each reporter plasmid (5 ng) and the LEF-1 expression plasmid (20 ng). Cells were lysed and luciferase activity was detected 48 h after transfection. (***p<0.001 by one-way ANOVA with Dunnett’s multiple comparison tests compared to basal activity; ^###p<0.001; ns, not significant compared to the value from the <i>TYR</i> promoter and LEF-1 by an unpaired Student’s t-test). <b>C</b> Binding of LEF-1 to the <i>TYR</i> promoter was analyzed by ChIP assay by precipitating with the indicated antibodies and normal mouse IgG, which was used as the negative control. The crosslinks were reversed at 65°C for 4 h and digested with proteinase K (Sigma-Aldrich) for 1 h at 45°C to remove proteins. A 230-bp <i>TYR</i> promoter fragment (-28 to -257 bp) was amplified by PCR, and the products were subjected to 2% agarose gel electrophoresis. Ten percent of the chromatin DNA used for immunoprecipitation was subjected to PCR and is indicated as ‘input’. The results were representative of at least three independent experiments.</p

<i>TYR</i> is a direct LEF-1 target gene.

<p><b>A</b> Schematic representation of the human TYR promoter sequence containing 380 bp (-300 bp to +80 bp) together with the potential LEF-1 binding sites (double underlined) and their flanking sequences. <b>B</b> TYR transcriptional activity determined by Luciferase activity assay. The <i>TYR</i>-Luc luciferase reporter plasmid was transiently transfected into melanoma UACC903 cells in combination with increasing amounts of LEF-1 expression vector. The basal luciferase level was set to 1. Data from all other transfections are presented as fold induction above this level. Luciferase activity was normalized by measuring β-galactosidase activity. Each value represents the mean ± SD of three replicates from a single assay. The results shown were representative of at least three independent experiments. (**p<0.01, ***p<0.001 compared to basal activity, unpaired Student’s t-test).</p