Effect of sample geometry on the phase boundary of a mesoscopic superconducting loop
Effect of sample geometry on the phase boundary of a mesoscopic superconducting loop
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DOI：
10.1103/physrevb.80.064511
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发表时间：
2009-08
影响因子：
3.7
通讯作者：
G. Berdiyorov;Suhong Yu;Zhili Xiao;F. Peeters;J. Hua;A. Imre;W. Kwok
中科院分区：
文献类型：
--
作者：
G. Berdiyorov;Suhong Yu;Zhili Xiao;F. Peeters;J. Hua;A. Imre;W. Kwok
通过输运测量研究了样品几何形状对纳米Nb圆环和方形圆环中超导态演化的影响。发现两种样品的电阻随温度的多级转变，这是由相同的超导材料制成的接触引线的效果有关。接近T{sub c 0}的H-T相图在抛物线背景的顶部显示出明显的周期性振荡，即，小帕克斯效应然而，振荡的幅度在圆形回路中比在方形样本中减小得更快。在非线性Ginzburg-Landau理论中进行了数值模拟，以显示样品几何形状对超导环结构中超导性成核的影响。
We studied the effect of sample geometry on the evolution of the superconducting state in nanoscale Nb circular and square loops by transport measurements. A multistage resistive transition with temperature is found for both samples, which is related to the effect of contact leads made from the same superconducting material. The H-T phase diagrams close to T{sub c0} show clear periodic oscillations on top of a parabolic background, i.e., Little-Parks effect. However, the amplitude of the oscillations decreases faster in the circular loop compared to the one in the square sample. Numerical simulations are conducted within the nonlinear Ginzburg-Landau theory to show the effect of sample geometry on the nucleation of superconductivity in superconducting loop structures.