Abstract

Magnons are excitations of magnetically ordered materials that correspond to spatial and temporal variations of the magnetic order parameter. In systems that spontaneously break rotational symmetry, these magnons are Nambu-Goldstone bosons, implying that, in the absence of long-range interactions, they should be gapped and, depending on the nature of the magnetic order parameter, should be either linearly or quadratically dispersing.

© 2014 Optical Society of America