Observation of the spontaneous vortex phase in the weakly ferromagnetic superconductor ErNi${}_2$B${}_2$C: A penetration depth study

Elbert E. M. Chia, M. B. Salamon, Tuson Park +3

The coexistence of weak ferromagnetism and superconductivity in ErNi${}_2$BC suggests the possibility of a spontaneous vortex phase (SVP) in which vortices appear in the ab…