Quantum finite automata: A modern introduction
  We present five examples where quantum finite automata (QFAs) outperform their classical counterparts. This may be useful as a relatively simple technique to introduce quantum computation concepts to computer scientists. We also describe a modern QFA model involving superoperators that is able to simulate all known QFA and classical finite automaton variants. 
A. C. Cem Say and Abuzer Yakaryilmaz
cs.FL cs.CC quant-ph