Transport measurements of the spin wave gap of thin Mn films

Temperature dependent transport measurements on ultrathin antiferromagnetic Mn films reveal a heretofore unknown non-universal weak localization correction to the conductivity which extends to disorder strengths greater than 100 k$Omega$ per square. The inelastic scattering of electrons off of gapped antiferromagnetic spin waves gives rise to an inelastic scattering length which is short enough to place the system in the 3d regime. The extracted fitting parameters provide estimates of the energy gap ($Delta = 16$ K) and exchange energy ($bar{J} = 320$ K).