Pinning, metastability and sliding of charge density waves in an electric field.

The static and dynamic behavior of a charge density wave, with random pinning forces and with or without a commensurate potential, under the application of an electric field is considered. A mode-mode coupling theory is introduced where the modes are the various length and time scales of the deformed charge density wave. As the field is increased, the charge density wave passes from a regime that is totally pinned to a regime where local depinning occurs without global depinning and then to a sliding regime. The a.c. response in all the regimes, metastability, hysteresis and non-linear behavior are discussed.