  The connection between coined and continuous-time quantum walk models has
been addressed in a number of papers. In most of those studies, the
continuous-time model is derived from coined quantum walks by employing
dimensional reduction and taking appropriate limits. In this work, we produce
the evolution of a coined quantum walk on a generic graph using a
continuous-time quantum walk on a larger graph. In addition to expanding the
underlying structure, we also have to switch on and off edges during the
continuous-time evolution to accommodate the alternation between the shift and
coin operators from the coined model. In one particular case, the connection is
very natural, and the continuous-time quantum walk that simulates the coined
quantum walk is driven by the graph Laplacian on the dynamically changing
expanded graph.
