SELF-CONSISTENT ANALYSIS OF SINGLE-PARTICLE EXCITATIONS IN A SPIN-DENSITY-WAVE ANTIFERROMAGNET

We present the results of a self-consistent weak-coupling calculation for the renormalized single-particle properties in an itinerant antife rromagnet. Multiple spin-wave excitations accompany the carrier motion and lead to incoherent contributions to the electronic spectrum. We e valuate the quasiparticle spectral weight and energy dispersion. In ag reement with strong-coupling theories we find the minimum of the dispe rsion of the quasihole energy to have momentum (+/-pi/2,+/-pi/2) and t he dispersion to be flat around the corners of the Brillouin zone. Ver y good agreement is achieved with available exact diagonalization data .