State Classification via a Random-Walk-Based Quantum Neural Network

In quantum information technology,crucial information is regularly encoded in different quantum states.To extract information,the identification of one state from the others is inevitable.However,if the states are nonorthogonal and unknown,this task will become awesomely tricky,especially when our resources are also limited.Here,we introduce the quantum stochastic neural network(QSNN),and show its capability to accomplish the binary discrimination of quantum states.After a handful of optimizing ...     

Ab Initio Molecular Dynamics Simulations on Structural Properties of Liquid In20Sn80

Ab initio molecular dynamics simulations on liquid ln2oSnso alloy are carried out at six different temperatures from 798 K to 1193 K. The temperature dependences of binding energy, volume, pair-correlation function and structure factor are studied. The first-peak position of our calculated pair correlation function is in agreement with the experimental data. A shoulder is reproduced in the high wave number side of the first peak in our calculated structure factor, implying the existence of the residual directional bonds of Sn atoms in liquid In20Sn80 alloy. The first-peak height of our calculated structure factor and the coordination number of Sn atom decrease more sharply in the low-temperature region from 798 K to 986 K than that in the high-temperature region from 986 K to 1193K, suggesting that a discontinuous structural change may occur at around 986K in liquid In20Sn80 alloy.     

“重子结构和重子相互作用”研讨会简讯

20 0 1年 4月 2日至 5日 ,中国高等科学技术中心和中国科学院高能物理研究所在北京联合举办了“重子结构和重子相互作用”研讨会 .研讨会邀请了在德国图宾根大学获博士学位、现在泰国大学任教的阎宇鹏教授做系列讲座 .高能核散射专家、法国南特大学的Ｗｅｒｎｅｒ教授做了顺访报告 .来自中国科学院高能物理研究所、理论物理研究所、北京大学、清华大学、南京大学、中国科学技术大学、南开大学、山东大学、广西师范大学及中国原子能科学研究院的4 0多位从事该方面研究工作的老、中、青研究人员和专家参加了研讨会 ,共提交了 2 5个学术报告 .…     

Population transfer in multilevel system through modified stimulated Raman adiabatic passage

Stimulated Raman adiabatic passage(STIRAP)has been successfully extended to multilevel system.Dur- ing the STIRAP process,the intermediate levels have notable population which is detrimental if these levels could decay to other levels through spontaneous emission.This paper proposes a novel method to reduce the intermediate level population during the STIRAP process.A complete population transfer can be achieved in this modified STIRAP even if the intermediate level decays to other levels.     

1,2,3-三氮杂苯-水复合物氢键相互作用

用密度泛函理论在B3LYP/6-31 G**水平上对1,2,3-三氮杂苯和水形成1:1、1:2和1:3复合物的基态氡键结构进行几何优化和性质计算．计算结果表明,复合物之间存在较强的氢键作用．所有稳定复合物结构中形成一个N…H-O氢键并终止于O…H-C氢键的氢键水链构型最稳定．氢键的形成是水分子中H-O键振动频率减小(红移)．NBO分析表明,最稳定的1:1、1:2和1:3复合物发生分子间电荷转移总量分别为0．0222e、0．0261e和0．0273e．同时,用含时密度泛函理论方法在TD-B3LYP/6-31 G**水平计算了1,2,3-三氮杂苯单体及其氢键复合物的第一1(n,π*)激发态的垂直激发能．     

奇特的"五夸克态"和重子中的五夸克成分

文章简要介绍了奇特的θ^＋五夸克态、质子中的奇异夸克成分和重子激发态中的五夸克成分等重子谱和重子结构方面的一些最新前沿进展．最新的高统计量实验结果表明，轰动一时的suudd五夸克态θ^＋（1540）很可能不存在．而最新的几个电弱相干实验给出一致的结果：质子的奇异磁矩和奇异半径很可能不为零，且均为正．理论分析表明，这意味着质子中的ssuud成分很可能主要是以夸克对有色集团的形式存在，而不是以传统的介子云无色集团的形式存在．对最轻的负宇称核子激发态N^＊（1535）一些性质的最新研究支持这种关于重子中的五夸克成分的新图像．     

Fe位Al掺杂对Sr2FeMoO6磁结构和磁输运性质的影响

研究了Sr2Fe1-xAlxMoO6(0≤x≤0.30)系列多晶样品的磁学和输运性质.室温X射线衍射谱图的精修结果显示Al3+掺杂没有改变样品的晶格结构,但提高了Sr2FeMoO6晶格的阳离子有序度.5K时样品的磁化曲线说明平均单位分子饱和磁矩随着Al含量的增加而下降,但平均单位Fe离子磁矩却逐渐提高.磁化曲线的拟合结果显示样品内反铁磁相互作用对饱和磁矩的贡献随着Al含量的增加而下降,说明一定量的Fe离子被Al替代后,抑制了样品内Fe-O-Fe反相边界的形成,从而提高了Sr2FeMoO6晶格的阳离子有序度和平均单位Fe离子磁矩.对饱和磁矩的分析表明非磁性Al3+离子掺杂会形成无磁相互作用的Mo-O-Al-O-Mo区,可以将原来较大的Mo-O-Fe亚铁磁区分割成许多小的区域,并且使这些亚铁磁区间的磁耦合作用变弱,从而提高了低场磁电阻效应.阳离子有序度的提高使来源于自旋相关电子在反相边界处散射的高场磁电阻明显降低,导致了样品的磁电阻在x=0.15时达到了最大值.     

Preparation of a Single Layer of Luminescent Nanocrystalline Si Structures by Laser Irradiation Method

KrF excimer laser annealing on ultrathin hydrogenated amorphous Si films with various initial Si thicknesses is carried out to obtain a single layer of nanocrystalline Si structures. It is found that Si nanograins can be obtained with the area density as high as 10^11 cm^-2 under the irradiation with suitable laser fluence. Raman and planar transmission electron microscopy are used to characterize the formation process of Si nanocrystals from amorphous phase. Moreover, a strong photoluminescence is observed at room temperature from well-relaxed nanocrystalline Si structures.     

程控数字交换机计费系统电路设计

针对实际的程控数字交换机计费系统，设计了一种在计算机和程控数字交换机之间进行并行通信的接口电路．该接口电路由大规模集成电路器件构成．对其硬件电路组成及工作原理作了较为详细的阐述，对计算机数据接收程序的设计也作了必要的说明，并给出了程序流图．     

YBa_2Cu_3O_7_薄膜热激发磁通蠕动研究

本文选择两块零电阻温度分别为82K 和71K 超导性能不同的簿膜徉品, 同步进行了电阻在外滋场中展宽的测量, 并用Palstra 所提出的Arrhenius 定律研究两样品热激活能的差别。实验发现样品热激活能随磁场增加线性下降. 由测量结果推出的不可逆线仍有B * -(l -T*/T_c_)**3/2形式. 关键词：