A decision procedure for well-formed linear quantum cellular automata

In this paper we introduce a new quantum computation model, the linear quantum cellular automaton. Well-formedness is an essential property for any quantum computing device since it enables us to define the probability of a configuration in an observation as the squared magnitude of its amplitude. We give an efficient algorithm which decides if a linear quantum cellular automaton is well-formed. The complexity of the algorithm is O(n2) in the algebraic model of computation if the input automaton has continuous neighborhood. © 1997 John Wiley & Sons, Inc. Random Struct. Alg., 11, 381–394 (1997)