Department of Physics and Optical Engineering, Ort Braude College, 21982 Karmiel, Israel.
J Phys Condens Matter. 2013 Nov 20;25(46):465702. doi: 10.1088/0953-8984/25/46/465702. Epub 2013 Oct 18.
We study the final distribution of the winding numbers in a 1D superconducting ring that is quenched through its critical temperature in the absence of magnetic flux. The study is conducted using the stochastic time-dependent Ginzburg-Landau model, and the results are compared with the Kibble-Zurek mechanism (KZM). The assumptions of the KZM are formulated and checked as three separate propositions. We find characteristic lengths and characteristic times for the processes we study. Besides the case of uniform rings, we examined the case of rings with several weak links. For temperatures close to or below Tc, the Ginzburg-Landau coherence length ξ(0)|T/Tc-1|(-1/2) does not play the role of the correlation length. In order to regard the winding number as a conserved quantity, it is necessary to allow for a short lapse of time during which unstable configurations decay. We found criteria for the validity of the 1D treatment. There is no lower bound for the final temperatures that permit 1D treatment. For moderate quenching times τQ, the variance of the winding number obeys the scaling
我们研究了在没有磁通的情况下通过临界温度淬火的一维超导环中涡旋数的最终分布。这项研究是使用随机时变的 Ginzburg-Landau 模型进行的,并将结果与 Kibble-Zurek 机制(KZM)进行了比较。KZM 的假设被表述为三个独立的命题,并进行了检查。我们为我们研究的过程找到了特征长度和特征时间。除了均匀环的情况外,我们还研究了具有几个弱连接的环的情况。对于接近或低于 Tc 的温度,Ginzburg-Landau 相干长度 ξ(0)|T/Tc-1|(-1/2) 不起关联长度的作用。为了将涡旋数视为守恒量,有必要允许不稳定构型在短时间内衰减。我们找到了一维处理的有效性的标准。允许一维处理的最终温度没有下限。对于中等淬火时间 τQ,涡旋数的方差服从 KZM 在平均场模型情况下预测的< n 2 >比例变 τ(-1/4)Q,对于 τQ ≲ 10(5)ħ/kBTc,依赖性较弱。我们还研究了在抑制规范场波动时系统的行为,并得到了在更宽的范围内服从< n 2 >比例变 τ(-1/4)Q 的结果。