Search

The precise measurement of minute displacements using light is a common practice in modern science and technology. The utilization of sound for precision displacement metrology remains scarce due to the diffraction limit of half-wavelength, while it holds crucial applications in some specific scenarios, such as underwater environments, biological tissues, and complex machinery components. Here, we propose an approach to super-resolution acoustic displacement metrology by introducing the concept of topological pairs in orbital meta-atoms, drawing inspiration from the analogy of Cooper pairs observed in spinful electrons. The topological pairs are conjugately formed to create two distinct pathways in mode space that enable robust generation of interference. This allows the realization of acoustic analogue of Malus's law and thereby enhances the resolution of displacement measurements. By incorporating a spiral twist configuration in orbital meta-atoms, we demonstrate the first acoustic prototype of a physical micrometer tailored for micron-scale displacement metrology. We observe experimentally a displacement resolving power of 1.2 μm at an audible frequency of 3.43 kHz, approximately 1/105 of the sound wavelength of 100 mm. Our work implies a new paradigm for precise displacement metrology within classical wave physics and lays the foundation for diverse acoustic applications. Precise displacement measurement via sound is crucial in science and engineering, yet limited by its low resolution. Here, the authors proposed the concept of topological pairs for achieving acoustic displacement metrology, and experimentally demonstrated an acoustic micrometer with resolving power of 1.2 μm at operating wavelength of 100 mm. [ABSTRACT FROM AUTHOR]

Efficiently fabricating a cavity that can achieve strong interactions between terahertz waves and matter would allow researchers to exploit the intrinsic properties due to the long wavelength in the terahertz waveband. Here we show a terahertz detector embedded in a Tamm cavity with a record Q value of 1017 and a bandwidth of only 469 MHz for direct detection. The Tamm-cavity detector is formed by embedding a substrate with an Nb5N6 microbolometer detector between an Si/air distributed Bragg reflector (DBR) and a metal reflector. The resonant frequency can be controlled by adjusting the thickness of the substrate layer. The detector and DBR are fabricated separately, and a large pixel-array detector can be realized by a very simple assembly process. This versatile cavity structure can be used as a platform for preparing high-performance terahertz devices and opening up the study of the strong interactions between terahertz waves and matter. Here the authors report a terahertz detector with a Q value of 1017, embedded in a Tamm cavity and offers a 469 MHz bandwidth. It features an Nb5N6 microbolometer in an Si/air DBR and metal reflector, with tunable resonant frequency via substrate layer thickness. [ABSTRACT FROM AUTHOR]

Superconducting nanocircuits, which are usually fabricated from superconductor films, are the core of superconducting electronic devices. While emerging transition-metal dichalcogenide superconductors (TMDSCs) with exotic properties show promise for exploiting new superconducting mechanisms and applications, their environmental instability leads to a substantial challenge for the nondestructive preparation of TMDSC nanocircuits. Here, we report a universal strategy to fabricate TMDSC nanopatterns via a topotactic conversion method using prepatterned metals as precursors. Typically, robust NbSe2 meandering nanowires can be controllably manufactured on a wafer scale, by which a superconducting nanowire circuit is principally demonstrated toward potential single photon detection. Moreover, versatile superconducting nanocircuits, e.g., periodical circle/triangle hole arrays and spiral nanowires, can be prepared with selected TMD materials (NbS2, TiSe2, or MoTe2). This work provides a generic approach for fabricating nondestructive TMDSC nanocircuits with precise control, which paves the way for the application of TMDSCs in future electronics. The practical device application of transition-metal dichalcogenide superconductors (TMDSCs) is limited by their environmental instability. Here, the authors report a generic, non-destructive, and scalable strategy to fabricate TMDSC nanocircuits via the topotactic conversion of prepatterned metallic precursors. [ABSTRACT FROM AUTHOR]

We propose a tunable multichannel plasmonic mid-infrared filter of a single graphene sheet depositing on a Fibonacci quasiperiodic structure. The transmission spectra are numerically analyzed by a finite-difference time-domain (FDTD) method, and the results show that the filtering properties of the proposed structure can be tuned by the chemical potentials of graphene, the width and depth of air grooves, and the refractive index of the substrate. The simulation results are discussed analytically by deducing the dispersion relation of surface plasmon polariton propagating on four layers structure of air/graphene/air/dielectric. The proposed structure may find potential applications in tunable filters, sensors, and integrated photonic circuits. [ABSTRACT FROM AUTHOR]