SPATIAL STRUCTURE OF SPIN POLARONS IN THE T-J MODEL

The deformation of the quantum Neel 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 funct ion for the quasiparticle, The results of various spin-correlation fun ctions relative to the position of the moving hole are discussed and s hown to agree with those available from small cluster calculations. An tiferromagnetic correlations in the direct neighborhood of the hole ar e reduced, but they remain antiferromagnetic even for J as small as 0. 1t. These correlation functions exhibit dipolar distortions in the spi n structure, which sensitively depend on the momentum of the quasipart icle. Their asymptotic decay with the distance from the hole is govern ed by power laws, yet the spectral weight of the quasiparticles does n ot vanish. [S0163-1829(98)03008-2].