Quantum Field Theory of the Pinned Density Wave

A model is discussed in which an electric field induces quantum nucleation of soliton-antisoliton pairs in a pinned charge or spin density wave. Coulomb blockade prevents pair creation until the electric field exceeds a sharp threshold value, which can be much smaller than the classical depinning field. We calculate the vacuum state energy and expectation value of the phase, which is treated as a quantum scalar field. We find that the phase can also be much smaller, below threshold, than predicted by classical ``sliding'' density wave models.