A concise review of Rydberg atom based quantum computation and quantum simulation

Quantum information processing based on Rydberg atoms emerged as a promising direction two decades ago.Recent experimental and theoretical progresses have shined exciting light on this avenue.In this concise review,we will briefly introduce the basics of Rydberg atoms and their recent applications in associated areas of neutral atom quantum computation and simulation.We shall also include related discussions on quantum optics with Rydberg atomic ensembles,which are increasingly used to explore quantum computation and quantum simulation with photons.     

Rigorous supermode solutions in a strong absorption slab waveguide and application to design of a waveguide photodetector

A rigorous supermode solution method in a strong absorption slab multilayer waveguide is performed.The method is directed toward finding solutions for a sophisticated complex determinant in a complex plane.The rigorous results are applied to design a waveguide photodetector that has a configuration of a vertical directional coupler.Absorption lengths of the supermodes and coupling length of the coupler are calculated based on an effective index approach by using the rigorous results of the strong absorption slab multilayer waveguide to optimize the directional coupling waveguide photodetector.     

爆炸作用驱动液体抛撒初始阶段数值仿真

 针对灭火战斗部引战配合设计,研究爆炸作用驱动液体（水基灭火剂）抛撒初始阶段的特性。依据典型灭火战斗部的结构建立数值仿真模型,采用LS-DYNA软件进行仿真计算,分别获得了加载系数（驱动装药与液体的质量比）对壳体破裂时间和壳体破裂初期液体/空气界面运动速度的影响规律,以及液体/空气界面后续的运动特性。进行了同条件下爆炸驱动水基灭火剂抛撒实验,得到了不同加载系数条件下壳体破裂初期液体/空气界面的运动速度。实验结果与数值仿真结果吻合良好,表明所采用的数值仿真方法具有正确性和有效性,对相关问题的研究具有重要参考价值。     

AIN纳米微粉的微波合成

Nanometer aluminum nitride powder with purity higher than 98wt% and diameter in the range of 5-80nm has been obtained by microwave heating using α-Al2O3、Al(OH)3、 colloidal Al(OH)3 as the source for aluminum, and phenolformaldehyde resin, char, nanometer carbon black powder as the source for carbon, respectively. The effect of the type of starting materials and synthesis conditions on the purity and the size of the nanometer AlN powder has been analyzed in this paper.     

Observation of E×B Flow Velocity Profile Change Using Doppler Reflectometry in HL-2A

A broadband, O-mode sweeping Doppler reflectometry designed for measuring plasma E×B flow velocity profiles is operated in HL-2A. The main feature of the Doppler reflectometry is its capability to be tuned to any selected frequency in total waveband from 26-40 GHz. This property enables us to probe several plasma layers within a short time interval during a discharge, permitting the characterization of the radial distribution of plasma fluctuations. The system allows us to extract important information about the velocity change layer, namely its spatial localization. In purely Ohmic discharge a change of the E×B flow velocity profiles has been observed in the region for 28 〈 r 〈 30cm if only the line average density exceeds 2.2×10^19 m^-3. The density gradient change is measured in the same region, too.     

Interfacial effect on the reverse of magnetization and ultrafast demagnetization in Co/Ni bilayers with perpendicular magnetic anisotropy

For static magnetic properties of the Co/Ni bilayers, macroscopic hysteresis loops and microscopic magnetic moment distributions have been determined by the object oriented micromagnetic framework(OOMMF). It is found that when the bilayer systems are fully decoupled, the magnetizations of the two phases reverse separately. The coercivity of the bilayers decreases to a valley value sharply with increasing interfacial exchange coupling and then rises slowly to a platform. On the other hand, we have carried out an atomistic simulation for the laser-induced ultrafast demagnetization of the Co/Ni bilayer. A larger damping constant leads to a faster demagnetization as well as a larger degree of demagnetization, which is consistent with the first-principle theoretical results. For the magnetization recovery process, the damping constant has different influences on the recovery time with various peak electron temperatures, which is ignored in previous atomistic simulations as well as the Landau–Liftshit–Bloch(LLB) micromagnetic calculations. Furthermore, as the interfacial exchange coupling increases, the ultrafast demagnetization curves for Co and Ni become coincident, which is a demonstration for the transition from two-phase phenomenon to single-phase phenomenon.     

弱光探测器中复合抛物面聚光镜

基于非成像光学的原理,设计并研制了一种用于弱光探测器的复合抛物面聚光镜.提出基于遗传算法的优化设计聚光镜电子光学系统的新方法,将探测器阳极对光电子的接收率作为遗传进化的目标函数,把复合抛物面聚光镜系统的几何结构参量和电参量作为优化设计的搜索变量,通过控制遗传算法的遗传进化方向,进行全局优化调整.仿真实验结果表明,优化后的聚光镜在会聚光线的同时可以对光电子实现有效的会聚.当入射角为30°时,光透过率高于75%,电子收集率为100%,可以满足具有反射式光电阴极和大探测面积的弱光探测器要求.     

纳米纤维状Sr3Al2O5Cl2:Eu2+,Tm3+的白色长余辉性能

采用高温固相法在800℃下制备出系列白色长余辉荧光粉Sr₃Al₂O₅Cl₂：Eu²⁺,Tm³⁺,并研究了它们的结构、形貌及发光性能。样品Sr_2.91Al₂O₅Cl₂：0.04Eu²⁺,0.05 Tm³⁺具有单一晶相和纳米纤维结构。该样品在紫外光激发下表现出两个很强的宽带发射（分别位于~448 nm和~590 nm）。它的余辉寿命大约是20 min。利用此种荧光粉所制作出的白光LED器件表现出很强的白光发射。     

双腔热解光腔衰荡光谱仪测量大气中NO2和RNO2

A two-channel thermal dissociation cavity ring down spectroscopy (CRDS) instrument has been built for in situ, real-time measurement of NO₂ and total RNO₂ (peroxy nitrates and alkyl nitrates) in ambient air, with a NO₂ detection limit of 0.10 ppbv at 1 s. A 6-day long measurement was conducted at urban site of Hefei by using the CRDS instrument with a time resolution of 3 s. A commercial molybdenum converted chemiluminescence (Mo-CL) instrument was also used for comparison. The average RNO₂ concentration in the 6 days was measured to be 1.94 ppbv. The Mo-CL instrument overestimated the NO₂ concentration by a bias of +1.69 ppbv in average, for the reason that it cannot distinguish RNO₂ from NO₂. The relative bias could be over 100% during the afternoon hours when NO₂ was low but RNO₂ was high.     

HT-7装置电子回旋辐射系统接收天线改进

为了提高HT-7装置上等离子体电子回旋辐射(ECE)超外差诊断系统的极向分辨率,根据高斯光学原理,分析了诊断系统天线的改进方案。优化了天线的圆形角锥喇叭尺寸和凸透镜参数以及在装置上的相对位置,使天线接收到的等离子体ECE异常模二次谐波辐射的高斯光束束半径只有30mm左右,能量的高斯光学性质损失不大于13%。