A heterogeneous zero-range process related to a two-dimensional walk   model
  We have considered a disordered driven-diffusive system defined on a ring. This system can be mapped onto a heterogeneous zero-range process. We have shown that the grand-canonical partition function of this process can be obtained using a matrix product formalism and that it is exactly equal to the partition function of a two-dimensional walk model. The canonical partition function of this process is also calculated. Two simple examples are presented in order to confirm the results. 
S. R. Masharian and F. H. Jafarpour
cond-mat.stat-mech cond-mat.dis-nn