Mj. Lercher et Jm. Wheatley, Breakdown of mode-mode coupling expansion for commensurate itinerant antiferromagnetism in two dimensions - art. no. 012403, PHYS REV B, 6301(1), 2001, pp. 2403
We consider the mode-mode coupling theory of two-dimensional commensurate i
tinerant antiferromagnets where Q spans the Fermi surface. It is shown that
quantum (finite frequency) terms in the mode-mode coupling expansion are s
ingular. The singularity is sufficiently strong that a mean-field-like quan
tum critical point does not exist.