The  paper of  the  month,  chosen  by  the Editor-in-Chief,  is  "Spontaneous Magnetization and Nonmagnetic Defect Effects in Mesoscopic s+ i s Superconductors"  by G. Wang, T.-Y. Han,  J. Li and H. Huang;

DOI: 10.12693/APhysPolA.147.317

In the present paper, the authors study iron-based superconductors with state without time reversal symmetry. The existence of states that break the time reversal symmetry has been proposed for some doping levels. It is shown in the paper that spontaneous magnetization appears near the extended impurities in these superconductors. A two-band model based on the Ginzburg-Landau theory is used to study the effect. Numerical solutions to the resulting equations are presented in the case of a small superconducting flake and in the case of four and eight impurities symmetrically placed inside superconductors. This is a nice example of the interplay between superconductivity and magnetism that leads to symmetry breaking. The paper will be of interest to a broad range of physicists interested in various aspects of symmetry breaking.

The Editor-in-Chief