Pinning of stripes in cuprate superconductors

We examine the effects of disorder on striped phases in high-temperature superconductors and related materials. In the presence of quenched disorder pinning, by the atomic lattice-which might give rise to commensuration effects-is irrelevant for two-dimensional stripe arrays on large length scales. As a consequence, the stripes have divergent displacement fluctuations and topological defects are present at all temperatures. Therefore, the positional order of the stripe array is short ranged with a finite correlation length even at zero temperature. Thus lock-in phenomena can exist only as crossovers but not as transitions. In addition, this implies the glassy nature of stripes observed in recent experiments.