%0 Journal Article
%T Non-relativistic Nambu-Goldstone modes associated with spontaneously broken space-time and internal symmetries
%A Michikazu Kobayashi
%A Muneto Nitta
%J Physics
%D 2014
%I arXiv
%R 10.1103/PhysRevLett.113.120403
%X We show that a momentum operator of a translational symmetry may not commute with an internal symmetry operator in the presence of a topological soliton in non-relativistic theories. As a striking consequence, there appears a coupled Nambu-Goldstone mode with a quadratic dispersion consisting of translational and internal zero modes in the vicinity of a domain wall in an O(3) sigma model, a magnetic domain wall in ferromagnets with an easy axis.
%U http://arxiv.org/abs/1402.6826v3