Deterministic Exclusion Process with a Stochastic Defect: Matrix-Product   Ground States
  We study a one-dimensional anisotropic exclusion model describing particles moving deterministically on a ring with a single defect across which they move with probability 0 < q < 1. We show that the stationary state of this model can be represented as a matrix-product state. 
Haye Hinrichsen and Sven Sandow (Weizmann Institute, Virginia   Polytechnic Institute)