Strong correlations and the anisotropy of acceptor states in insulating La(2-x)Sr(x)CuO(4)
We use the Green's function formalism to discuss the role of strong correlations to the spatial structure of acceptor states doped into a two-dimensional Mott-Hubbard antiferromagnetic insulator. When the scattering between doped carriers, at the nesting wave vector ${\bf Q}=(\pi,\pi)$, is strong enough to produce a momentum dependent scattering rate, $\Gamma_{\bf k}$, the corresponding acceptor states become spatially anisotropic. As an example, we calculate the spatial structure of an acceptor state bound to an attractive two-dimensional Dirac delta potential, for a simple form of $\Gamma_{\bf k}$. We then discuss the role of such spatial anisotropy for the understanding of an apparent discrepancy between low temperature transport data and photoemission spectra in lightly doped La(2-x)Sr(x)CuO(4).