Spatial structure of spin polarons in thet−Jmodel

The deformation of the quantum Néel state induced by a spin polaron is analyzed in a slave fermion approach. Our method is based on the self-consistent Born approximation for the Green’s function and wave function for the quasiparticle. The results of various spin-correlation functions relative to the position of the moving hole are discussed and shown to agree with those available from small cluster calculations. Antiferromagnetic correlations in the direct neighborhood of the hole are reduced, but they remain antiferromagnetic even for $J$ as small as $0.1t$. These correlation functions exhibit dipolar distortions in the spin structure, which sensitively depend on the momentum of the quasiparticle. Their asymptotic decay with the distance from the hole is governed by power laws, yet the spectral weight of the quasiparticles does not vanish.