Decoherence in a quantum walk on the line

Abstract

We have studied how decoherence affects a quantum walk on the line. As expected, it is highly sensitive, consisting as it does of an extremely delocalized particle. We obtain an expression for the rate at which the standard deviation falls from the quantum value as decoherence increases and show that it is proportional to the number of decoherence "events" occuring during the walk.

QCMC02 proceedings with added extra eps figure (embedded) and section headings, 5 pages