Long-range entanglement is an important aspect of the topological orders, so efficient methods to characterize the long-range entanglement are often needed. In this regard, topological entanglement entropy (TEE) is often used for such a purpose but the experimental observation of TEE in a topological order remains a challenge. Here, we propose a scheme to observe TEE in the topological order by constructing specific minimum entropy states (MESs). We then experimentally construct the classical microwave analogs of the MESs and simulate the nontrivial topological order with the TEE in Kitaev toric code, which is in agreement with theoretical predictions. We also experimentally simulate the transition from Z₂ topologically ordered state to topologically trivial state.

Subarray is widely used in array antennas to decrease the system complexity, which would also increase the sidelobes during scanning. To solve this problem, subarray partition solutions with larger coverage and lower sidelobes are selected from a series of results generated by search algorithms. However, searching for an appropriate result of a large array is time-consuming. In this study, to search subarray solutions of full coverage with less time, we introduce two pruning processes in Algorithm X. Additionally, a pair of coefficients associated with the sidelobes is adopted for further pruning and reducing the sidelobes. Numerical experiments have been carried out and verified the effectiveness and the performance of the proposed method.

This paper presents a design of a triangular slot-loaded planar rectangular antenna array for wideband millimeter-wave (mm-wave) 5G communication systems. The proposed array realizes an overall size of 35.5 × 14.85 mm². To excite the array elements, a four-way broadband corporate feeding network was designed and analyzed. The proposed array offered a measured impedance bandwidth in two different frequency ranges, i.e., from 23 to 24.6 GHz and from 26 to 45 GHz. The single-antenna element of the array consists of a rectangular patch radiator with a triangular slot. The partial ground plane was used at the bottom side of the substrate to obtain a wide impedance bandwidth. The peak gain in the proposed array is ≈12 dBi with a radiation efficiency of >90%. Furthermore, the array gives a half-power beamwidth (HPBW) of as low as 12.5°. The proposed array has been fabricated and measured, and it has been observed that the measured results are in agreement with the simulated data.

A three-dimensional reconstruction algorithm based on line laser rotation scanning is proposed. The rotating platform vision measurement system is designed. The system calibration method consisting of laser, camera and turntable is studied. The axis-eye calibration algorithm is introduced to register the point cloud in the same coordinate. In the system, the camera driven by the turntable is rotated to scan the target object for three-dimensional measurement. The method can obtain the point cloud information of the object by linear laser rotation scanning, and further recover the geometric shape of the three-dimensional visible surface of the object, which not only meets the requirements of the three-dimensional reconstruction target, but also verifies the feasibility and effectiveness of the system.

Sparse arrays have gained increasing research attention due to their potential to reduce system cost and weight. However, current studies on sparse array synthesis often overlook the physical dimensions of the antennas and only consider the distance constraints of antenna centers. In this communication, we propose a novel matrix constraints method for the sparse planar array synthesis, taking into account the actual area occupied by each antenna unit. The proposed method introduces a matrix that relates the aperture lattices to each candidate antenna; this matrix is then used as a spatial constraint for the antennas. The synthesis problem, aimed at achieving a low sidelobe level, is formulated as a mixed-integer optimization problem under this matrix constraint. To obtain the array layouts efficiently, the synthesis problem is relaxed to a compressed sensing problem and subsequently solved using a combination of re-weighted l ₁ minimization convex optimization and the integer genetic algorithm. Numerical experiments and full-wave simulations were conducted, verifying the effectiveness of the proposed method.

A novel high-throughput spectrometer with a wide-slit is presented. In conventional spectrometers, the slit limited the light throughput. Here, the slit is replaced with a much wider one (200 μm) to increase throughput. A beam splitter is utilized to construct a dual-path optics to measure both non-dispersed and dispersed light intensity which comes from the wide-slit. While the dispersed light intensity is result of the non-dispersed light convoluted spectrum of the source, the spectrum can be acquired by solving the inverse problem of deconvolution. Experiments show that the reconstructed spectra achieved almost the same resolution measured by traditional spectrometer, while throughput and peak signal-to-noise ratio (PSNR) are improved dramatically.