2025/09/08 by Xusheng Wang, Lianyi He, Wang, Xusheng +3 · 1 citation
Engineering · Physics and Astronomy · #Superconducting Materials and Applications #Physics of Superconductivity and Magnetism
paper · pdf · doi:10.48550/arxiv.2509.06889
Ferromagnetic superconductors, where ferromagnetism and superconductivity coexist despite their antagonism, exhibit strikingly diverse behaviors. Depending on the interplay between the ferromagnetic exchange field and the superconducting condensate, superconductivity may vary with temperature monotonically, non-monotonically, or even reentrantly, all of which can be tuned by external magnetic fields. Here, we present a unified theoretical framework and construct comprehensive phase diagrams that capture these regimes and predict new phenomena, including doublereentrant superconductivity. We further demonstrate how magnetic fields drive systematic shifts between distinct temperature-dependent behaviors, thereby explaining recent experimental results and predicting new transitions. In addition, we show that the field-induced enhancement of superconductivity, previously observed as a slight increase in Tc, can under certain conditions become dramatic.