高温超导体环流演示仪

利用永磁铁对超导样品进行激励,产生的超导环流不衰减,由此原理制做了高温超导环流演示仪,该仪器可演示零电阻现象、环流磁场及超导体电阻与温度的关系.     

利用迈克耳孙干涉仪重建蜡烛火焰温度场

利用教学实验中的迈克耳孙干涉仪,进行蜡烛火焰温度场的测量.对干涉条纹进行了处理和细化,并分别用阿贝尔变换法和环带法对蜡烛火焰的温度场进行了计算,得到蜡烛火焰横截面上温度场的定量结果.     

磁场中夸克物质的黏滞系数

研究了磁场中夸克非轻子弱作用过程的反应率和黏滞系数. 改进了在弱磁场情况下的近似计算方法, 给出了非轻子过程的反应率与夸克物质的体黏滞系数的表达式, 显示出在弱磁场情况下, 黏滞系数的温度依赖关系与零磁场情况下一致, 但黏滞系数的大小依赖磁场的强度.     

强外加电场与大调制度下光折变动力学光栅形成研究

强外加电场与大调制度在光折变效应的研究中已经得到了广泛应用。采用PDECOL算法,严格求解光折变带输运方程,得到外加电场时不同调制度下光折变晶体中随时间变化的空间电荷场、载流子浓度,并讨论了外加电场对它们的影响。通过将物质方程与耦合波方程联立数值求解,可得到光折变光栅形成过程中两波耦合增益系数以及光束条纹相位的变化。模拟结果表明,在强外加电场作用下,两束记录光之间的光强与相位耦合都得到了增强,而原有的解析式忽视了强外加电场与大调制度对空间电荷场相位耦合的影响,此时不再适用。同时发现折射率光栅与记录光束条纹均发生弯曲,并不再保持平行。     

高斯光束在外加空间调制电场的光折变晶体中的演化

研究了高斯光束在外加空间调制电场的光折变晶体中的演化,结果表明,在不同的外加调制电场作用下高斯光束的光场分布会随着外电场变化而被调制。重点研究了同相位和反相位以及相位差为π/2的高斯光束在外加空间调制电场的光折变晶体中的相互作用,在外加空间分布线性增加电场作用下出现了许多新的实用特性,通过调整外加电场分布,可以让两同相位相干光靠得更近而不发生融合,也可以让两靠得很近的反相位光束可控偏转,还可以控制相位差为π/2的两相干光束进行能量转移。这种连续变化的电场可以用阶梯分布的电场替代,为工程实现提供了可能。     

Noninvariant zeta-function regularization in quantum Liouville theory

We consider two possible zeta-function regularization schemes of quantum Liouville theory. One refers to the Laplace–Beltrami operator covariant under conformal transformations, the other to the naive noninvariant operator. The first produces an invariant regularization which however does not give rise to a theory invariant under the full conformal group. The other is equivalent to the regularization proposed by A.B. Zamolodchikov and Al.B. Zamolodchikov and gives rise to a theory invariant under the full conformal group.     

磁场构型的影响及用于RIKEN的RIBF项目的新型ECR离子源

We measured the main plasma parameters(density of electron,temperature of electron and ion confinement time)and beam intensity of various heavy ions as a function of B_(min).The B_(min) strongly affects the field gradient at the resonance zone,consequently the plasma parameters and beam intensity are changed. Based on these experimental results,we started to construct new 18GHz ECRIS and make a detailed design of the 28GHz SC-ECRIS for RIKEN RI beam factory project.     

Electron–phonon effect on the ground-state binding energy of hydrogenic impurity in quantum-well wire in presence of an electric field

The hydrogenic impurity binding energy in rectangular quantum well wire including both barriers of finite height and an applied electric field are studied. The polaron effects on the ground-state binding energy in electric field are investigated by means of Landau-Pekar variation technique. The results for the binding energy as well as polaronic correction are obtained as a function of the size of the wire, the applied electric field and the position of the impurity. Our calculations are compared with previous results in quantum wires of comparable dimensions.     

The role of nucleation field of media in heat-assisted magnetic probe recording

We characterize a method of heat-assisted magnetic probe recording on perpendicular media. Heating source is field emission current from a scanning tunneling microscope (STM) tip. Recording media are three kinds of magnetic films, Co/Pt, CoNi/Pt, and Co/Pd multilayers with different nucleation fields. Pulses with amplitude of 5 V were applied between the STM tip and the recording medium. Experiments show that magnetic marks with an average size of 180 nm were formed on both Co/Pt and CoNi/Pt films whose nucleation fields are greater than their saturation magnetization. No marks were observed on the Co/Pd film whose nucleation field is smaller than its saturation magnetization. A model is built to simulate the dynamic process of domain formation in probe-based magnetic recording system. Simulation results agree with experiments and it explains the effect of the nucleation field of medium in perpendicular recording.