Breakdown of the critical state in the ferromagnetic superconductor EuFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$

William Robert Fern, Joseph Alec Wilcox, Tong Ren +3

There are very few materials in which ferromagnetism coexists with superconductivity due to the destructive effect of the magnetic exchange field on singlet Cooper pairs. The iron-…