From Hunds insulator to Fermi liquid: Optical spectroscopy study of K doping in BaMn${}_2$As${}_2$

D. E. McNally, S. Zellman, Z. P. Yin +7

We present optical transmission measurements that reveal a charge gap of 0.86 eV in the local moment antiferromagnetic insulator BaMn${}_2$As${}_2$, an order of magnitude larger than p…