Börcsök B, Komori S, Buzdin A I, Robinson J W A
Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, United Kingdom.
Université Bordeaux, CNRS, LOMA, UMR- 5798, F-33400, Talence, France.
Sci Rep. 2019 Apr 4;9(1):5616. doi: 10.1038/s41598-019-41764-3.
The development of superconducting memory and logic based on magnetic Josephson junctions relies on an understanding of junction properties and, in particular, the dependence of critical current on external magnetic flux (i.e. Fraunhofer patterns). With the rapid development of Josephson junctions with various forms of inhomogeneous barrier magnetism, Fraunhofer patterns are increasingly complex. In this paper we model Fraunhofer patterns for magnetic Josephson junctions in which the barrier magnetic susceptibility is position- and external-magnetic-field dependent. The model predicts anomalous Fraunhofer patterns in which local minima in the Josephson critical current can be nonzero and non-periodic with external magnetic flux due to an interference effect between magnetised and demagnetised regions.
基于磁性约瑟夫森结的超导存储器和逻辑器件的发展依赖于对结特性的理解，特别是临界电流对外部磁通量的依赖性（即夫琅禾费图样）。随着具有各种形式非均匀势垒磁性的约瑟夫森结的迅速发展，夫琅禾费图样变得越来越复杂。在本文中，我们对势垒磁化率与位置和外部磁场相关的磁性约瑟夫森结的夫琅禾费图样进行了建模。该模型预测了反常的夫琅禾费图样，其中由于磁化区域和退磁区域之间的干涉效应，约瑟夫森临界电流中的局部最小值对于外部磁通量可以是非零且非周期性的。
