本文详细研究了外加高频振荡电场对超导体块体和表面超导临界成核场的影响。从线性化含时Ginzburg-Landau（TDLG）理论出发，利用变分原理，我们证明了量子谐振子与超导体成核的量子谐振子和量子双振子与有限样品表面成核的量子双振子之间的相似性。Cook { \it et al} \cite{cook}的有效哈密顿方法被用来包含外部施加的高振荡电场的影响。用基态能量法计算了临界形核场比。从这两个近似理论得到的结果符合得很好的精确结果的情况下，无驱动系统，建立了这两个近似理论的有效性。观察到，与没有电场的情况（$\varepsilon_0=0$）相比，高振荡电场实际上增加了超导体的体临界成核场（$H_{c_2}$）以及表面临界成核场（$H_{c_3}$）。但外加快速振荡电场对表面临界成核场的强化作用大于体相临界成核场，即$H_{c_3}$的增加是$H_{c_2}$的1.6592倍。
英文摘要：
The effect of an externally applied high frequency oscillating electric field on the critical nucleation field of superconductivity in the bulk as well as at the surface of a superconductor is investigated in details in this work. Starting from the linearized time dependent Ginzburg-Landau (TDLG) theory and using the variational principle we have shown the analogy between a quantum harmonic oscillator with that of the nucleation of superconductivity in bulk and a quantum double oscillator with that of the nucleation at the surface of a finite sample. The effective Hamiltonian approach of Cook {\it et al} \cite{cook} is employed to incorporate the effect of an externally applied highly oscillating electric field. The critical nucleation field ratio is also calculated from the ground state energy method. The results obtained from these two approximated theories agree very well with the exact results for the case of undriven system which establishes the validity of these two approximated theories. It is observed that the highly oscillating electric field actually increases the bulk critical nucleation field ($H_{c_2}$) as well as the surface critical nucleation field ($H_{c_3}$) of superconductivity as compared to the case of absence of electric field ($\varepsilon_0=0$). But the externally applied rapidly oscillating electric field accentuates the surface critical nucleation field more than the bulk critical nucleation field i.e. the increase of $H_{c_3}$ is 1.6592 times larger than that of $H_{c_2}$.
Multiple charge density waves and superconductivity nucleation at antiphase domain walls in the nematic pnictide Ba$_{1-x}$Sr$_{x}$Ni$_{2}$As$_{2}$
超导性如何与电荷或电子有序相互作用是量子材料研究中心尚未解决的重大问题之一。Ba $_{1-x}$ Sr $_{x}$ Ni $_{2}$ As $_{2}$（BSNA）是一种电荷有序的磷属元素化物超导体，最近被证明在量子相变（$x_c=0.7$）附近由于电子涨落而表现出六倍的超导电性增强。然而，超导性是反常的，$0.4 < x< x_c$的电阻转变发生在比比热反常更高的温度下。利用X射线散射，我们发现了一个新的电荷密度波（CDW）在BSNA在这个组成范围。CDW与两个晶格参数的周期相当，并且不同于先前在该材料中报道的两个CDW。我们认为，反常的输运行为产生的异质超导形核在反相畴壁的CDW。我们还提出了新的数据上的不相称的CDW，以前确定为单向的，表明这是一个旋转对称的，“4 $Q$“状态与$C_4$对称性。我们的研究建立了BSNA作为一种罕见的材料，包含三个不同的CDW，和一个令人兴奋的测试平台，用于研究CDW，CDW和SC订单之间的耦合。
Superconducting Geometric Potential and Curvature-Enhanced Superconductivity in Curved Thin Films
Guangxi University of Science and Technology（广西科技大学）；Yangzhou Polytechnic Institute（扬州职业技术学院）；School of Physics and Electronic Engineering, Linyi University（临沂大学物理与电子工程学院）
Characterization of photoinduced normal state through charge density wave in superconducting YBa$_2$Cu$_3$O$_{6.67}$
高温超导铜酸盐的正常态是高温超导研究的重要课题之一。然而，与高磁场研究相比，光致正常态的理解仍然是难以捉摸的。在这里，我们探讨了光诱导正常状态的YBa $_2$铜$_3$ O $_{6.67}$（YBCO）通过电荷密度波（CDW）与时间分辨共振软X射线散射，以及高磁场X射线散射。在人们根据之前的光谱预测猝灭超导态的非平衡态中，我们实验观察到与平衡态中所示的超导性和CDW之间的竞争类似的类比。我们进一步观察到，通过光泵浦，CuO $_2$平面上的对态被破坏，导致了三维CDW前驱关联的成核，揭示了光致CDW与磁场下的现象相似.最后，这些发现提供了一个关键的线索，光致正常状态的特性显示出坚实的相似之处，在平衡条件下的磁场。
