Weak localization of magnons in a disordered two-dimensional antiferromagnet

摘要

We propose the weak localization of magnons, in a disordered two-dimensional anuierromagnet. We derive the longitudinal thermal conductivity k_(xx) for magnons of a disordered Heisenberg antiferromagnet in the linear-response theory with the linear-spin-wave approximation. We show that the back scattering of magnons is enhanced critically by the parucle-particle-type multiple impurity scattering. This back scattering causes a logarithmic suppression of k_(xx) with the length scale in two dimensions. We also, argue a possible effect of inelastic scattering on the temperature dependence of k_(xx) . This weak localization is useful to control turning the magnon thermal current on and off.