The Striped Phase in Presence of Disorder and Lattice Potentials

We study the influence of disorder and lattice effects on the striped phase and the incommensurate spin fluctuations of the cuprates and nickelates. Starting from a phenomenological model of a discrete quantum string on a lattice with disorder, we derive the renormalisation group equations in leading order in the lattice and disorder strength. Three regimes are identified, the quantum membrane phase, the flat phase pinned by the lattice and the disorder pinned phase. We compare our results with measurements on nickelates and cuprates and find good agreement.