Von Neumann Entanglement and Decoherence in Two Dimensional Quantum   Walks
  Using the concept of von Neumann entropy, we quantify the information content of the various components of the quantum walk system, including the mutual information between its subsystems (coin and position) and use it to give a precise formulation of the measure of entanglement between subsystems. 
Clement Ampadu
math-ph math.MP quant-ph