Unlocking Transition for Modulated Surfaces and Quantum Hall Stripes

We develop a sine-Gordon model of layered systems of two-dimensional modulated surfaces and one dimensional stripes, and demonstrate that these systems can undergo a Kosterlitz-Thouless transition in which the modulations unlock as a result of thermal or quantum fluctuations, respectively. The unlocked phase is interpreted as an anisotropic crystal in which soliton-antisoliton pairs proliferate. The properties of such a state for modulated stripes in quantum Hall systems and its possible relevance to recent anomalies in transport data are discussed.