A new kind of step-flow growth mode is proposed, which adopts sidewall as step source on patterned GaN substrate. The terrace width of steps originated from the sidewall was found to change with the growth temperature and ammonia flux. The growth mechanism is explained and simulated based on step motion model. This work helps better understand the behaviors of step advancement and puts forward a method of precisely modulating atomic steps.

随着社会信息化程度的逐步提升，人们对光纤通信系统容量的需求持续增长。信道损伤一直是限制光纤通信容量提升的关键因素，信道损伤补偿作为光纤通信系统的基础性功能和关键技术也在不断改进。近年来，将深度学习应用到光纤通信信道损伤补偿中更是吸引了不少研究人员的关注。文章介绍了近年来应用于光纤通信中的常见深度学习模型，阐述了深度学习技术在光纤通信系统信号损伤补偿方面的发展情况。

优化量子线路对于提高量子算法的计算效率和降低资源成本至关重要, 特别是在布尔函数构建的Oracle线路中。该优化过程分为两个关键阶段，第一个阶段基于最小权匹配算法对Oracle线路相同受控点的MCT门进行重排序, 最小化生成线路的门数; 第二个阶段利用模板匹配的方式进一步降低线路的门数和代价。实验结果表明, 相较于优化工具RCViewer⁺, 在4~10位量子比特数下, Deutsch-Jozsa算法下的Oracle线路门数降低了约48.3%, 代价减少了约64.5%; Grover算法下的Oracle线路门数降低了约25.0%, 代价减少了约18.2%。

The InGaN films and GaN/InGaN/GaN tunnel junctions (TJs) were grown on GaN templates with plasma-assisted molecular beam epitaxy. As the In content increases, the quality of InGaN films grown on GaN templates decreases and the surface roughness of the samples increases. V-pits and trench defects were not found in the AFM images. p⁺⁺-GaN/InGaN/n⁺⁺-GaN TJs were investigated for various In content, InGaN thicknesses and doping concentration in the InGaN insert layer. The InGaN insert layer can promote good interband tunneling in GaN/InGaN/GaN TJ and significantly reduce operating voltage when doping is sufficiently high. The current density increases with increasing In content for the 3 nm InGaN insert layer, which is achieved by reducing the depletion zone width and the height of the potential barrier. At a forward current density of 500 A/cm², the measured voltage was 4.31 V and the differential resistance was measured to be 3.75 × 10^?3 Ω·cm² for the device with a 3 nm p⁺⁺-In_0.35Ga_0.65N insert layer. When the thickness of the In_0.35Ga_0.65N layer is closer to the “balanced” thickness, the TJ current density is higher. If the thickness is too high or too low, the width of the depletion zone will increase and the current density will decrease. The undoped InGaN layer has a better performance than n-type doping in the TJ. Polarization-engineered tunnel junctions can enhance the functionality and performance of electronic and optoelectronic devices.

Edge detection for low-contrast phase objects cannot be performed directly by the spatial difference of intensity distribution. In this work, an all-optical diffractive neural network (DPENet) based on the differential interference contrast principle to detect the edges of phase objects in an all-optical manner is proposed. Edge information is encoded into an interference light field by dual Wollaston prisms without lenses and light-speed processed by the diffractive neural network to obtain the scale-adjustable edges. Simulation results show that DPENet achieves F-scores of 0.9308 (MNIST) and 0.9352 (NIST) and enables real-time edge detection of biological cells, achieving an F-score of 0.7462.

随机游走模型能够准确预测筒仓内无摩擦颗粒系统的堵塞概率，但是对于有摩擦的颗粒系统，该模型的适用范围至今尚不清楚。搭建了基于面阵CCD相机的测量装置，通过图像法测量堵塞拱的特征参数，发现当堵塞拱上相邻两个颗粒的夹角与颗粒位置之间满足负线性关系，并且流量大于8.3 g/s时，随机游走模型可以准确预测筒仓的堵塞概率。实验结果拓展了随机游走模型的适用范围，为工业生产中筒仓装置的调控过程提供了参考依据。

Specific contact resistance ρc to p-GaN was measured for various structures of Ni/Pd-based metals and thin (20–30 nm thick) p-InGaN/p⁺-GaN contacting layers. The effects of surface chemical treatment and annealing temperature were examined. The optimal annealing temperature was determined to be 550 °C, above which the sheet resistance of the samples degraded considerably, suggesting that undesirable alloying had occurred. Pd-containing metal showed ~35% lower ρc compared to that of single Ni. Very thin (2–3.5 nm thick) p-InGaN contacting layers grown on 20–25 nm thick p⁺-GaN layers exhibited one to two orders of magnitude smaller values of ρc compared to that of p⁺-GaN without p-InGaN. The current density dependence of ρc, which is indicative of nonlinearity in current-voltage relation, was also examined. The lowest ρc achieved through this study was 4.9 × 10^–5 Ω·cm² @J = 3.4 kA/cm².Specific contact resistance ρc to p-GaN was measured for various structures of Ni/Pd-based metals and thin (20–30 nm thick) p-InGaN/p⁺-GaN contacting layers. The effects of surface chemical treatment and annealing temperature were examined. The optimal annealing temperature was determined to be 550 °C, above which the sheet resistance of the samples degraded considerably, suggesting that undesirable alloying had occurred. Pd-containing metal showed ~35% lower ρc compared to that of single Ni. Very thin (2–3.5 nm thick) p-InGaN contacting layers grown on 20–25 nm thick p⁺-GaN layers exhibited one to two orders of magnitude smaller values of ρc compared to that of p⁺-GaN without p-InGaN. The current density dependence of ρc, which is indicative of nonlinearity in current-voltage relation, was also examined. The lowest ρc achieved through this study was 4.9 × 10^–5 Ω·cm² @J = 3.4 kA/cm².