Spontaneous magnetization of the O(3) ferromagnet at low temperatures
Spontaneous magnetization of the O(3) ferromagnet at low temperatures
We investigate the low-temperature behavior of ferromagnets with a spontaneously broken symmetry $\mathrm{O}(3)\ensuremath{\rightarrow}\mathrm{O}(2).$ The analysis is performed within the perspective of nonrelativistic effective Lagrangians, where the dynamics of the system is formulated in terms of Goldstone bosons. Unlike in a Lorentz-invariant framework (chiral perturbation theory), where loop graphs are suppressed …