EFREMOV, D.V., BETOURAS, J.J. and CHUBUKOV, A., 2008. Nonanalytic behavior of two-dimensional itinerant ferromagnets. Physical Review B - Condensed Matter and Materials Physics, 77, 220401(R), (4pp.)
We consider an ordered ferromagnet in the vicinity of a T=0 transition into a paramagnet. We
show that the free energy and the transverse and longitudinal static susceptibilities contain nonanalyticities
which destroy a continuous second-order transition. Depending on the parameters, the
transition either becomes first-order, or occurs via an intermediate spiral phase.