Moiré pattern

About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.

Conductive film, display device equipped with the same and conductive film evaluation method

Abstract: PROBLEM TO BE SOLVED: To provide a conductive film having a mesh pattern which can inhibit creation of moire to vastly improve visibility; and provide an evaluation method of the pattern.SOLUTION: A conductive film which is composed of a parallelogram wiring pattern to which irregularities are provided to have a rectangular wiring pattern in which irregularity within a predetermined range is provided to an angle of each diamond shape of a diamond wiring pattern where a moire rating index calculated from an evaluation value of a moire of each color obtained by providing the action of human visual responsivity depending on a monitoring distance to each moire intensity of equal to or more than an intensity threshold value out of moire intensities in a frequency of each moire equal to or less than a frequency threshold value in the frequency and the intensity of the moire, which are calculated with respect to each color from first and second peak frequencies and first and second peak intensities of 2DFFT spectrum of transmissivity image data of the diamond wiring pattern before the irregularities are provided and brightness image data of a pixel arrangement pattern of each color at monochromatic light lighting becomes equal to or less than an evaluation threshold value.

Ultralow-level all-optical self-switching in a nanostructured moiré superlattice.

Abstract: We report an all-optical self-switching performed at an ultralow-level of intensity in a nanostructured moiré superlattice on a silicon platform. The moiré superlattice was formed by twisting two sets of triangular lattices in a silicon membrane in the same layer with a twist angle of 9.43°. The near flatband was formed, and the electric field was well confined in the center of the superlattice, which enabled all-optical switching under an ultralow intensity when the Kerr nonlinearity of silicon was considered. The intensity, which was reduced to 300 W/m2 and even 20 W/m2, can cause the transmittance of the nanostructure to change from 0 to 80% under x- and y-polarized pump light, respectively, and could be further decreased by optimizing the nanostructure or nonlinear materials. The results indicate that moiré superlattices fabricated from nonlinear materials are promising for integrated all-optical devices.

Strong Structural and Electronic Coupling in Metavalent PbS Moiré Superlattices.

Abstract: Moiré superlattices are twisted bilayer materials in which the tunable interlayer quantum confinement offers access to new physics and novel device functionalities. Previously, moiré superlattices were built exclusively using materials with weak van der Waals interactions, and synthesizing moiré superlattices with strong interlayer chemical bonding was considered to be impractical. Here, using lead sulfide (PbS) as an example, we report a strategy for synthesizing moiré superlattices coupled by strong chemical bonding. We use water-soluble ligands as a removable template to obtain free-standing ultrathin PbS nanosheets and assemble them into direct-contact bilayers with various twist angles. Atomic-resolution imaging shows the moiré periodic structural reconstruction at the superlattice interface due to the strong metavalent coupling. Electron energy loss spectroscopy and theoretical calculations collectively reveal the twist-angle-dependent electronic structure, especially the emergent separation of flat bands at small twist angles. The localized states of flat bands are similar to well-arranged quantum dots, promising an application in devices. This study opens a new door to the exploration of deep energy modulations within moiré superlattices alternative to van der Waals twistronics.

Narrow band filter designed from Bravais-Moiré two-dimensional photonic crystal

Abstract: This work investigates the light propagation through a narrow-band filter based on a two-dimensional photonic crystal with Bravais-Moiré lattice and dielectric elements of circular cross section. We report on the corresponding gap mapping as a function of the radius of dielectric cores as well as the dispersion relations of TM modes for a sample 2D structure and for the waveguide system built of defect lines within such crystal, coupled to a microcavity. The proposed design is tested via numerical simulations, using the finite element method, aiming at its eventual biosensing performance. Cavity resonant frequencies were determined for different biological molecules, finding values of quality factor up to Q = 54858.1. A linear response against changes in the index of refraction of different analyzed substances was found for the filter. Sensibility of up to 13086▒nm/RIU (equivalent to 73.3▒GHz/RIU), and figure of merit up to 3112.32▒RIU −1 were determined. This points at the possible use of this kind of filters for developing THz-range biosensors with label-free medical and biological applications. • Bravais-Moiré twod’dimensional photonic crystals • Photonic band gap mapping, dispersion relations and transmittance • Photonic crystal cavity simulations and filtering analysis • Molecule sensing, high quality factors and figures of merit

Moiré disorder effect in twisted bilayer graphene

Abstract: We theoretically study the electronic structure of magic-angle twisted bilayer graphene with disordered moir\'e patterns. By using an extended continuum model incorporating non-uniform lattice distortion, we find that the local density of states of the flat band is hardly broadened, but splits into upper and lower subbands in most places. The spatial dependence of the splitting energy is almost exclusively determined by the local value of the effective vector potential induced by heterostrain, whereas the variation of local twist angle and local moir\'e period give relatively minor effects on the electronic structure. We explain the exclusive dependence on the local vector potential by a pseudo Landau level picture for the magic-angle flat band, and we obtain an analytic expression of the splitting energy as a function of the strain amplitude.