用灯泡演示电子热发射的实验

实验电原理图如下图所示: 用一个60～100W的白炽灯泡灯丝作为阴极,将一块宽约40ram长约100mm的金属板制成半圆形紧扣在灯泡的顶端作为阳极,一台0～5kV的可调高压电源作为阳极电源,用一     

Quantum Correlations in a Family of Two-Qubit Separable States

Quantum correlations in a family of two-qubit separable classical-quantum correlated states are intensively studied with four diferent approaches,namely,quantum discord[Phys.Rev.Lett.88(2002)017901],measurementinduced disturbance(MID)[Phys.Rev.A 77(2008)022301],ameliorated MID[J.Phys.A:Math.Theor.44(2011)352002]and quantum dissonance[Phys.Rev.Lett.104(2010)080501].Quantum correlations captured with diferent approaches are compared and discussed so that their three distinct features are exposed.     

Quantum Correlations in Werner Derivatives

Quantum correlations in Werner derivatives are studied with two diferent approaches,i.e.,measurementinduced disturbance(MID)[Phys.Rev.A 77(2008)022301]and ameliorated MID(AMID)[J.Phys.A 44(2011)352002].They are derived via strict deductions with MID while numerically calculated via the measurement optimization with AMID.Interestingly,quantum correlations captured with both approaches are completely coincident.Moreover,some distinct features of the quantum correlations and their underlying physics are exposed via analyses and discussions.     

匀质球壳模型的溯源与拓展

从一道高考选择题出发,追溯题源、深挖内涵、拓展应用,以引发平时课堂教学中对物理思维方法渗透的期待,同时引导学生学会科学迁移,有效地培养学生创新精神和实践能力.     

Four-Electron Quantum Ring in a Magnetic Field

We study a quantum ring （QR） with four electrons in a perpendicular external magnetic field B by exact diagonalization. The low-lying spectra of the QR as a function orb are obtained. A phase diagram is presented indicating that the angular momentum and the spin of the ground state of the QR may jump when B and/or the radius of the QR vary, and a corresponding analysis is performed. By plotting the density functions of the QR, the ground-state configuration is found to be a regular quadrangle. Furthermore, the features of the ground-state persistent current are revealed.     

引力的曲率平方理论

利用法坐标对局部等效原理、以及局部等效原理在构造曲率平方可重整拉氏量中的作用进行了论证．得到了曲率平方引力的场方程、其线性近似以及有质引力粒子的Ｙｕｋａｗａ势的表式．     

Revisiting Quantum Secure Direct Communication with W State

The quantum secure direct communication protocol recently proposed by Cao and Song [Chin. Phys. Left. 23 （2006）290] （i.e., the C-S QSDC protocol） is revisited. A security leak is pointed out. Taking advantage of this leak, an eavesdropper may adopt the intercept-measure-resend strategy to attack the quantum channel such that in the C-S QSDC protocol the secret message can be completely eavesdropped. To fix the leak, the original version of the C-S QSDC protocol is revised. As a consequence, the security is improved and assured at least in the case of an ideal quantum channel.     

SU(2)Kac-Moody代数与Virasoro代数表示间的关系和Modular不变性

利用Modular变换,我们讨论了SU(2)Kac-Moody代数可积表示与Virasoro代数么正表示的关系,同时,我们也就证明了这个关系是Modular不变的。从这个关系出发,考查了SU(2)Kac-Moody代数和Virasoro代数表示空间的算子乘积代数的聚合法则的对应关系。