摘要：Optical control of exotic properties in strongly correlated electron materials is very attractive owing to their potential applications in optical and electronic ***,we demonstrate a vertical heterojunction made of a correlated electron oxide thin film VO_(2) and a conductive 0.05 wt% Nb-doped TiO_(2) single crystal,whose metal-insulator transition(MIT)across the nanoscale heterointerface can be efficiently modulated by visible light *** magnitude of the MIT decreases from ~350 in the dark state to ~7 in the illuminated state,obeying a power law with respect to the light power *** junction resistance is switched in a reversible and synchronous manner by turning light on and *** optical tunability of it is also exponentially proportional to the light power density,and a 320-fold on/off ratio is achieved with an irradiance of 65.6 mW cm^(-2) below the MIT *** the VO_(2) thin film is metallic above the MIT temperature,the optical tunability is remarkably weakened,with a one-fold change remaining under light *** results are co-attributed to a net reduction(~15 meV)in the apparent barrier height and the photocarrier-injection-induced metallization of the VO_(2) heterointerface through a photovoltaic effect,which is induced by deep defect level transition upon the visible light irradiance at low ***,the optical tunability is minimal,resulting from the quite weak modulation of the already metallic band structure in the Schottky-type junction above the MIT *** work enables a remotely optical scheme to manipulate the MIT,implying potential uncooled photodetection and photoswitch applications.

摘要：我们成功地设计出一种新型的Si电子束蒸发器 ,并将它应用于Ge/Si(111)量子点的生长。由于采用悬臂式设计 ,它完全克服了高压短路的问题。电子束蒸发器的性能试验表明 ,稳定输出功率可以控制输出稳定的Si束流。应用这种电子束蒸发器可以在 70 0℃ ,成功沉积出平整的单晶Si薄膜。进一步的试验表明 ,在这种缓冲层表面可以自组装生长出Ge量子点。

摘要：该文研究了基于可重构智能超表面(RIS)赋能的无线通信系统的安全传输问题。在研究的模型中,一个用户通过智能超表面连接到接入点,而窃听者窃听了从用户发送到基站的信号。因此,有必要设计一个合适的智能超表面反射向量来解决窃听问题。这个问题被表述为一个优化问题,其目标是通过共同优化智能超表面反射向量和智能超表面元件的数量来最大化安全能效,该安全能效定义为安全速率与系统总能耗的比值。这是一个非凸优化问题,传统方法是难以解决的。为了解决这个问题,提出了一种利用新兴的深度学习(DL)技术的新算法,以找到近似最优的智能超表面反射向量并确定近似最优的genie-aided反射元素数量。仿真结果表明,该方法达到了近似最优算法的最佳安全能效的96%。