Strong enhancement of superconducting T-c in ferromagnetic phases - art. no. 127003

It is shown that the critical temperature for spin-triplet, p-wave supercon ductivity mediated by spin fluctuations is generically much higher in a Hei senberg ferromagnetic phase than in a paramagnetic one, due to the coupling of the magnons to the longitudinal magnetic susceptibility. Together with the tendency of the low-temperature ferromagnetic transition in very clean Heisenberg magnets to be of first order, this qualitatively explains the ph ase diagram recently observed in UGe2.