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We report the experimental demonstration of a class of ultrasonic metasurfaces made of patterned silicon thin wafers partially covered by Si3N4 film that exhibit over 24 dB of sound transmission loss around 0.7 MHz, which is caused by the cancelation of sound waves emitted by the resonant Si3N4 membrane and the ones through the silicon backbone in each unit cell. These metasurfaces are expected to have high reflection with little total loss even at ultrasonic frequency. They could be good candidates as the building blocks for low-loss cavities, phase zone plates, and other underwater acoustic metamaterials. As the working principle is scalable, it provides guidance for the designs of audible underwater sound barriers as well.
Transmission electron microscopy, scanning transmission electron tomography, and electron energy loss spectroscopy were used to characterize three-dimensional artificial Si nanostructures called metalattices, focusing on Si metalattices synthesized b
Permalloy films with one-dimensional (1D) profile modulation of submicron periodicity are fabricated based on commercially available DVD-R discs and studied using ferromagnetic resonance (FMR) method and micromagnetic numerical simulations. The main
Mechanical control of magnetic properties in magnetostrictive thin films offers the unexplored opportunity to employ surface wave acoustics in such a way that acoustic triggers dynamic magnetic effects. The strain-induced modulation of the magnetic a
We present high-frequency ultrasonic measurements on the filled skutterudite SmOs$_4$Sb$_{12}$ under hydrostatic pressure. The results clarify that the 4$f$ electrons in this compound transform from delocalized at ambient pressure to localized at hig
Single atoms can be considered as basic objects for electron microscopy to test the microscope performance and basic concepts for modeling of image contrast. In this work high-resolution transmission electron microscopy was applied to image single pl