Cappellaro Alberto, Salasnich Luca
Dipartimento di Fisica e Astronomia "Galileo Galilei", Università di Padova, via Marzolo 8, 35131, Padova, Italy.
CNR-INO, via Nello Carrara, 1 - 50019, Sesto Fiorentino, Italy.
Sci Rep. 2020 Jun 3;10(1):9088. doi: 10.1038/s41598-020-65790-8.
Within the Ginzburg-Landau functional framework for the superconducting transition, we analyze the fluctuation-driven shift of the critical temperature. In addition to the order parameter fluctuations, we also take into account the fluctuations of the vector potential above its vacuum. We detail the approximation scheme to include the fluctuating fields contribution, based on the Hartree-Fock-Bogoliubov-Popov framework. We give explicit results for d = 2 and d = 3 spatial dimensions, in terms of easily accessible experimental parameters such as the Ginzburg-Levanyuk number Gi, which is related to the width of the critical region where fluctuations cannot be neglected, and the Ginzburg-Landau parameter κ, defined as the ratio between the magnetic penetration length and the coherence one.
在超导转变的金兹堡 - 朗道泛函框架内，我们分析了临界温度的涨落驱动位移。除了序参量涨落外，我们还考虑了矢量势在其真空值之上的涨落。基于哈特里 - 福克 - 博戈留波夫 - 波波夫框架，我们详细阐述了包含涨落场贡献的近似方案。我们给出了二维（d = 2）和三维（d = 3）空间维度的明确结果，这些结果是用易于获取的实验参数表示的，比如金兹堡 - 列万纽克数Gi，它与涨落不可忽略的临界区域宽度有关；以及金兹堡 - 朗道参数κ，其定义为磁穿透长度与相干长度之比。
