Effect of mesoscopic inhomogeneities on local tunneling density of states in cuprates

Abstract

We carry out a theoretical analysis of the momentum dependence of the Fourier-transformed local density of states in the superconducting cuprates within a model considering the interference of quasiparticles scattering on quenched impurities. The impurities introduce an external scattering potential, which is either nearly local in space or can acquire a substantial momentum dependence due to a possible strong momentum dependence of the electronic screening near a charge modulation instability. The key effect that we introduce is an additional mesoscopic disorder aiming to reproduce the inhomogeneities experimentally observed in scanning tunneling microscopy. The crucial effect of this mesoscopic disorder is to give rise to pointlike spectroscopic features, to be contrasted with the curvelike shape of the spectra previously calculated within the interfering-quasiparticle schemes. It is also found that stripelike charge modulations play a relevant role to correctly reproduce all the spectral features of the experiments.