Spin-wave renormalization in two-dimensional antiferromagnets with finite hole density

Abstract

When holes are doped into a two-dimensional antiferromagnet the spin excitations are renormalized. This renormalization is calculated for finite hole densities. The spin-wave spectrum is found to soften instantaneously upon doping, and the spectral functions are significantly broadened. With 0.1 hole per site the spin-wave spectrum collapses. The implications on the hole mobility is discussed briefly.