Nb／AlO_x／Nb约瑟夫森结阳极氧化的实验研究

本文描述在ＣＯＲＮＩＮＧ７０５９玻璃衬底上用磁挖射频溅射法制备Ｎｂ／ＡｌＯｘ／Ｎｂ约瑟夫森结的质量和工艺条件的相关规律。由Ｘ荧光测量和扫描电镜观测，分别研究膜的Ａｒ浓度ＣＡｒ与偏压Ｖｂ的关系和膜的表面形貌与结构。并对Ｖｂ和气体压力ＰＡｒ对膜应力和结构的影响作探讨．对Ｎｂ／ＡｌＯｘ／Ｎｂ约瑟夫森的介面及各种氧化参数的影响研究发现：膜的厚度、氧化温度、层序、薄的自然氧层的存在等因素对介面的质量有大的影响。通过对体现结特性的阳极氧化电压谱图的测量比较，我们确认介面的陡度与结的质量相关，即与超导特性相关。ＡｌＯｘ阻挡层的Ａｌ层厚度的最小最佳值为０．７ｎｍ。

赵森:很闪耀,很明星

14岁入行,19岁当上厨师长。从最低层做到厨师长,赵森只用了五年的时间。爱笑,爱闹,爱唱歌,爱做主持人,赵森所在之处,总是目光的焦点。80后,有理想,思想解放,个性张扬,这些在赵森身上展露无余。

YBaCuO薄膜桥结的弱化制备及其保护措施浅探

该文介绍的是有选择性地弱化ＹＢａＣｕＯ／ＺｒＯ２（１００）薄膜制备Ｊｏｓｅｐｈｓｏｎ桥结的一种简洁方法，分析、讨论了该方法影响结参数的各种因素。最后。文中还给出了我们对薄膜器件的保护措施所进行的初步探索结果；使用涂覆有机物、射频溅射ＺｒＯ２等几种方法．取得了较好的效果。

Schrdinger Cat States in a Mesoscopic Josephson Junction

To study the nonclassical effects of the mesoscopic Josephson junction in the presence of a nonclassical microwave, the mesoscopic Josephson junction and the field were both treated quantum mechanically, and the external field approximation was used. It is shown that if the external field is in the coherent state and the state of the junction is initially prepared in the vacuum state, the state of the junction can evolve into a quantum superposition of two coherent states. The Schrdinger cat states can be produced in a mesoscopic Josephson junction.

Zero-Point Energy and Fluctuation in a Field-Josephson Junction-Coupled System

To investigate the interaction of a mesoscopic Josephson junction with a single mode quantized electromagnetic field, the diagnonalizing process of the coupled system Hamiltonian was performed by using an unitary transformation. Zero? point energy and zero? point fluctuation of the coupled system were shown. For the ground state of the coupled system, the quantum fluctuations of the flux and charge operators in the field and junction subsystems can exhibit smaller quantum noise than the zero point fluctuations of the individual subsystems. Thus, when the coupled system is in its lowest energy state, which means that no radiation appear, the two subsystems exhibit nonclassical behavior.

Dynamic Behavior of Voltage Across Small Capacitance Josephson Junction

Aim To study the dynamic behavior of voltage across small capacitance Josephson junction. Methods A model of the mesoscopic Josephson junction coupled with a single mode quantized radiation field was used. Results A Gaussian type envelope factor exhibiting quantum collapse and revival(CR) phenomenon was obtained. Conclusion It is shown that for the squeezed state the time evolution of the voltage can exhibit drastically quantum CR phenomenon.

联华快客重新定义便利店

从模仿到自主创新,联华快客在中国便利店市场找到了一条属于自己的发展道路。中国便利店看上海,上海作为中国便利店密度极高的城市,其竞争程度可见一斑。要想在竞争如此激烈的市场环境中脱颖而出,在精细化管理、不断创新的同时,更需要对消费者进行细腻的认识与分析。联华快客作为土生土长的民族品牌历经17年,终于在竞争激烈的便利店行业站稳脚跟。

Quantum Fluctuation Properties in Mesoscopic Josephson Junction

An effective bosonic Hamiltonian describing the interaction of a mesoscopic Josephson junction with a quantized radiation field is studied. It is shown that when the field is initially in a coherent state and the junction initially in its lowest energy level state, the state of the coupled field-mesoscopic Josephson junction system can evolve to a squeezed state. A detailed analysis about the quantum fluctuation of the coupled system is given.

Quantum Dynamics of Two Capacitively Coupled Superconducting Islands via josephson Junctions

In this paper, we consider a system consisting of two capacitively coupled superconducting islands viaJosephson junctions. We show that it can be reduced to two coupling harmonic oscillators under certain conditions,and can be solved exactly in terms of a displacing transformation, a beam-splitter-like transformation, and a squeezingtransformation. It is found that the system evolves by a rotated-squeezed-coherent state when the system is initially in acoherent state. Quantum dynamics of the Cooper pairs in the two superconducting islands are investigated. It is shownthat the number of the Cooper pairs in the two islands evolves periodically.

Continuous Variable Entanglement of Two Mesoscopic Josephson Junctions Induced by a Thermal Radiation Field

The continuous-variable （CV） entanglement between two mesoscopic Josephson junctions is studied and the time-dependent characteristic function in Wigner representation for the Josephson junction subsystem driven by a singlemode thermal field is analytically obtained. It is found that an initial lowest energy state of the junction subsystem can evolve into a two-mode entangled Gaussian state through the interaction with the thermal radiation field. Furthermore, we investigate the influence of the temperature on the entanglement of the junctions and find that the CV entanglement of the two junctions shows the critical behavior with respect to the temperature.

Appearance of Spatial-Temporal Noise in Super-conducting Junction and Its Effect on Transport of Electron Pairs

Transport of electron pairs in super-conducting junction with spatial-temporal noise is investigated. We show that the spatial-temporal noise can produce the current of the electron pairs, which stems from a symmetry breaking of the system induced by the correlation of the spatial-temporal noise with the phase difference. It is found that there is a positive current for the electron pairs, exhibiting a peak with increasing the values of some parameters of the noises. The results provide a theoretical foundation for the further investigation of the super-conducting junction.

Teleportation for an Unknown Entangled State Without Any Joint Measurement via Josephson Charge Qubits

An experimentally feasible scheme for teleportation of an arbitrary unknown entangled state is proposed. Our scheme is based on Josephson charge qubits, where we do not need any joint measurement. Moreover the successful probability and fidelity of the teleportation can both reach 1.0. The current scheme can be realized within the current experimental technology.

Josephson Current in Superconductor-Ferromagnet／Insulator／d-Wave Superconductor Junctions

Solving the Bogoliubov-de Gennes equation, the energy levels of bound statesare obtained in the ferromagnetic superconductor. The Josephson currents in a ferromagneticsuperconductor/Insulator/d-wave superconductor junction are calculated as a function of the exchangefield, temperature, and insulating barrier strength. It is found that the Josephson criticalcurrent is always suppressed by the presence of exchange Geld h and depends on crystalline axisorientation of d-wave superconductor.

Localized Asymmetric Atomic Matter Waves in Two-Component Bose-Einstein Condensates Coupled with Two-Photon Microwave Field

We investigate localized atomic matter waves in the two-photon microwave field. Interestingly, the oscillations two-component Bose-Einstein condensates coupled by of localized atomic matter waves will gradually decay and finally become non-oscillating behavior even if existing coupling field. In particular, atom numbers occupied in two different hyperfine spin states will appear asymmetric occupations after some time evolution.

dc Josephson Effect in s-Wave Superconductor/Ferromagnet Insulator/p-Wave Superconductor Junctions

The Josephson currents in s-wave superconductor/ferromagnet insulator/p-wave superconductor（s/FI/p） junctions are calculated as a function of temperature and the phase taking into account the roughness scattering effect at interface. The phase dependence of the Josephson current I （φ） between s-wave and px-wave superconductor is predicted to be sin（2φ）. The ferromagnet scattering effect, the barrier strength, and the roughness strength at interface suppress the dc currents in s/FI/p junction.

Short-Time Decoherence of Solid-State Qubit at Optimal Operation Points

We investigate the short-time decoherence of a solid-state qubit under Ohmic noise at optimal operation points. The decoherence is analyzed by maximum norm of the deviation density operator. It is shown that at the temperature T = 3 mK, the loss of the fidelity due to decoherence is much smaller than the DiVincenzo low decoherence criterion, which means that the mode/may be an optimal candidate of qubit for quantum computation.

Cavity-Induced Self-Trapping of a Bose Josephson Junction

We investigate the self-trapping of a Bose Josephson junction, which is dispersively coupled to a driven optical cavity. The cavity-induced nonlinearity is presented analytically, and its effect results in the appearance of the self-trapping for the Bose-Einstein condensates in the Josephson oscillation regime. In addition, there exists competition between the nonlinearities induced by the interatomic interaction and by the driven cavity for the emergences of self-trapping. Our results show that the driven cavity can be utilized as a possible tool to produce the self-trapping for the condensates with weak interatomic interaction.

On Bosonic Magnetic Flux Operator and Bosonic Faraday Operator Formula

In the literature about mesoscopic Josephson devices the magnetic flux is considered as an operator, the fundamental commutative relation between the magnetic flux operator and the Cooper-pair charge operator is usually preengaged. In this paper we show that such a relation can be deduced from the basic Bose operators＇ commutative relation through the entangled state representation. The Faraday formula in bosonic form is then equivalent to the second Josephson equation. The current operator equation for LC mesoscopic circuit is also derived.

Josephson Effect in FS/I/N/I/FS Tunnel Junctions

The Bogoliubov de Gennes equation is applied to the study of coherence effects in the ferromagnetic superconductor/insulator/normal metal/insulator/ferromagnetic/superconductor （FS/I/N/I/FS） junction. We calculated the Josephson current in FS/I/N/I/FS as a function of exchange field in ferromagnetic superconductor, temperature, and normal metal thickness. It is found that the Josephson critical current in FS/I/N/I/FS exhibits oscillations as a function of the length of normal metal. The exchange field always suppresses the Josephson critical current Ip for a parallel configuration of the magnetic moments of two ferromagnetic superconductor （FS） electrodes. In the antiparallel configuration, the Josephson critical current IAv at the minimum values of oscillation increases with the exchange field for strong barrier strength and at low temperatures.

Indelible Rules of Josephson Coupling Energy and Zero-Point Energy in High-Tc Cuprates

This paper shows that the Josephson coupling energy and the zero-point energy have indelible rules on the superfluid density and the superconductivity in the high-Tc cuprates. This paper also shows that the values of Tc at underdoped and overdoped regions are determined by the damage conditions of the phase coherence in the classical and the quantum XY-models, respectively.