Limit Theorems for Decoherent Two Dimensional Quantum Walks
  In this paper we consider the model with decoherence operators introduced by [Brun,T.A, et.al, Phys.Rev.A 67 (2003) 032304] which has recently been considered in the two-dimensional setting by [Ampadu,C., Brun-Type Formalism for Decoherence in Two Dimensional Quantum Walks, Communication in Theoretical Physics To Appear, arXiv:1104.2061 (2011)] to obtain the limit of the decoherent quantum walk. 
Clement Ampadu
quant-ph math-ph math.MP