Fig. 1
From: Evidence of spontaneous vortex ground state in an iron-based ferromagnetic superconductor
Classification of magnetic superconductors that may host the spontaneous vortex (SV) phase. The left panels show superconducting ferromagnets (SFMs), while the right panels describe ferromagnetic superconductors (FSCs). a, b, \({H_{{\rm{int}}}}(0) >H_{{\rm{c1}}}^*(0)\); c, d, \(H_{{\rm{c1}}}^*(0) > {H_{{\rm{int}}}}(0)\). See the text for the definitions of H int and \(H_{{\rm{c1}}}^*\). M and M’ denote Meissner states, and NF stands for a non-superconducting ferromagnetic state. Here the upper critical fields, \(H_{{\rm{c2}}}^*(0)\), are assumed to be much larger than \(H_{{\rm{c1}}}^*(0)\) and H int(0)
