Structure of spin polarons in the spin-fermion model forCuO2planes

Abstract

We investigate the spectral functions and various spin-correlation functions relative to the position of the moving oxygen hole in the quantum Néel state formed by copper spins in CuO 2 planes. Solving the problem in a self-consistent Born approximation we have found the spectral functions with the sector of Zhang-Rice states coexisting with higher energy oxygen states, which agree qualitatively with the experimental data in insulating Sr 2 CuO 2 Cl 2 . The antiferromagnetic correlations are reduced in the neighborhood of the hole but remain antiferromagnatic and the correlation functions can exhibit similar dipolar distortions as reported in the context of the t-J model. The spectral weight of the quasiparticle decreases as 1/L with increasing size of L ϫL clusters for the realistic parameters, but remains finite in the thermodynamic limit of CuO 2 planes.