THE SUPERCONDUCTIVITY IN Al-DOPEDY_(1-x)Al_xBa_2Cu_3O_y

本文系统地分析了在Ｙ１－ｘＡｌｘＢａ２Ｃｕ３Ｏｙ（ｘ＝０～０．７）中用Ａｌ替代Ｙ的替代效应．我们发现当ｘ＜０．４时，Ａｌ主要替代在Ｙ位，引起结构畸变，从而导致氧含量的减少和Ｏ－Ｔ相变，转变温度随Ａｌ含量增加而下降．当掺杂量大于０．４，Ａｌ开始占据Ｃｕ（１）和Ｃｕ（２）位，样品变为四方结构，Ｔｃ迅速下降．ＸＰＳ分析表明，Ａｌ的位置依赖于掺杂量，随掺杂浓度的增加Ａｌ依次替代Ｙ，Ｃｕ（１），Ｃｕ（２）．同时我们观察到Ｔｃ和ＣｕＯ２平面间相互作用的正比关系．     

Macroscopic resonant tunneling in an rf-SQUID flux qubit

We have observed the macroscopic resonant tunneling of magnetic flux between macroscopically distinct quantum states in a superconducting flux qubit.The dependences of the macroscopic resonant tunneling on the barrier height of the potential well,the flux bias and the initial state are investigated.Detailed measurements of the tunneling rate as a function of the flux bias reveal the feature of the quantum noise in the superconducting flux qubit.     

利用超导量子电路模拟拓扑量子材料

近年来,探索新的拓扑量子材料、研究拓扑材料的新奇物理性质成为凝聚态物理领域的一个热点.但是,由于合成、测量等手段的限制,人们难以在真实材料中实现和观测很多理论预言的材料及其物理性质,促使量子模拟日益成为研究量子多体系统的一个重要手段.作为全固态器件,超导量子电路是一个在扩展性、集成性、调控性上都具有巨大优势的人工量子系统,是实现量子模拟的重要方案.本文总结了利用超导量子电路对时间-空间反演对称性保护的拓扑半金属、Hopf-link半金属和Maxwell半金属等拓扑材料的量子模拟,显示出超导量子电路在模拟凝聚态物理系统方面具有广阔前景.     

Demonstration of quantum permutation parity determine algorithm in a superconducting qutrit

A quantum algorithm provides a new way in solving certain computing problems and usually faster than classical algorithms. Here we report an implementation of a quantum algorithm to determine the parity of permutation in a single three-dimensional(3D) superconducting transmon qutrit system. The experiment shows the capacity to speed up in a qutrit,which can also be extended to a multi-level system for solving high-dimensional permutation parity determination problem.     

气相色谱-串联质谱法同时测定柴胡舒肝丸10种挥发性成分

建立气相色谱-串联质谱法测定柴胡舒肝丸挥发性成分藁本内酯、α-香附酮、十六烷酸、去氢木香内酯、人参炔醇、厚朴酚、和厚朴酚、大黄酚、大黄素甲醚、β-谷甾醇含量的方法。称取5 g柴胡舒肝丸样品,以乙酸乙酯为提取溶剂,样品浸泡30 min,冰水浴超声提取10 min,以气相色谱-串联质谱法对10种挥发性成分定性,内标法定量。10种挥发性成分在对应质量浓度范围内与色谱峰面积线性关系良好,相关系数（r）均大于0.995,样品加标回收率为93.4%～102.8%,测定结果的相对标准偏差为1.2%～5.1%(n=6)。该方法重复性高、稳定性和精密度良好、专属性强、操作简便,适用于柴胡舒肝丸多组分的质量控制。     

约瑟夫森器件中的宏观量子现象及超导量子计算

超导体中的电子结成库珀对，凝聚到可以用一个宏观波函数来描绘的能量基态，该波函数的位相是代表了成百万库珀对集体运动的宏观变量．以约瑟夫森结为基础元件的超导约瑟夫森器件，使人们能够控制并测量一个超导体的位相和库珀对数目，因此是研究宏观量子现象的理想系统．文章回顾了约瑟夫森器件中的宏观量子现象研究的发展历程，介绍了当前超导约瑟夫森器件在量子计算中的重要应用，并对它们的未来作了简要的展望．     

基于快速定点突变研究含硒人Zeta型谷胱甘肽硫转移酶1c-1c的催化活性

先将人Zeta型谷胱甘肽硫转移酶1c-1c(hGSTZ1c-1c)中非催化中心的Cys-137,Cys-154,Cys-165和Cys-205突变为Ser,然后将催化中心14,15和17位的3个氨基酸残基突变为Cys,再利用半胱氨酸缺陷型大肠杆菌表达系统将其特定地转化为Sec,即把GPx的催化基团引入到hGSTZ1c-1c中,高效地获得了具有谷胱甘肽过氧化物酶(GPx)活力的模拟酶.其中制备的3个含硒突变体15C,14C/15C和17C均显示出明显的GPx活力.对非含硒突变体性质研究发现,Ser-14或Ser-15任何一个残基发生突变都会导致hGSTZ1c-1c的GST活力几乎丧失,表明Ser-14和Ser-15在催化反应中发挥着重要作用,但前者主要参与底物结合,后者更侧重于催化.     

Landau-Zener-Stckelberg interference in a multi-anticrossing system

We propose a universal analytical method of studying the dynamics of a multi-anticrossing system subjected to driving by a single large-amplitude triangle pulse,within a time scale smaller than the dephasing time.Our approach can explain the main features of the Landau-Zener-Stuckelberg interference patterns recently observed in a tripartite system [Nature Communications 1 51 (2010)].In particular,we focus on the effect of the size of the anticrossing on interference and compare the calculated interference patterns with numerical simulations.In addition,a Fourier transform of the patterns can extract the information about the energy level spectrum.     

Tuning rf-SQUID flux qubit system's potential with magnetic flux bias

At an extremely low temperature of 20 mK, we measured loop current in a tunable rf superconducting quantum interference device (SQUID) with a dc-SQUID. By adjusting the magnetic flux applied to the rf-SQUID loop (Φ_f) and the small dc-SQUID (Φ_f^cjj), respectively, the potential shape of the system can be fully controlled in situ. Variations of transition step and overlap size in switching current with the barrier flux bias are analyzed, from which we can obtain some relevant device parameters and built up a model to explain the experimental phenomenon.