2003/08/07 by Naoum Karchev, Karchev, Naoum
Physics and Astronomy · #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/0308134
4 pages, 2 figures
arxiv created 2003/08/07 · arxiv updated 2009/12/01
It is assumed that U atoms in UGe2 have a number of f electrons appropriate to give them each a spin s=1 as well as one extra itinerant electron which may equally well be on one or other U atom. The dynamical degrees of freedom are spin-s operators of localized spins and spin-1/2 fermi operators of itinerant electrons. Applying hydrostatic pressure changes the bandwidths of spin-up and spin-down itinerant electrons in different way, which leads to decreasing of the contribution of the fermions to the magnetization keeping the spin-fermion interaction unchanged. In turn the local spin-fermion interaction leads to ferromagnetic superconductivity. The model accounts, in a quantitative and natural way, for the characteristics of the coexistence of superconductivity and ferromagnetism in UGe2, including many of the key experimental results: metamagnetic transitions, quantum transition from ferromagnetism to ferromagnetic superconductivity, the position of the highest superconducting critical temperature etc.