Kondacs, A. and Watrous, J. (1997) On the Power of Quantum Finite State Automata. Proceedings of the 38th Annual Symposium on Foundations of Computer Science, Miami, 66-75.
http://dx.doi.org/10.1109/SFCS.1997.646094

has been cited by the following article:

• TITLE: 1-Way Multihead Quantum Finite State Automata

  AUTHORS: Debayan Ganguly, Kingshuk Chatterjee, Kumar Sankar Ray

  KEYWORDS: 1-Way Quantum Finite State Automaton (1QFA), k-Letter Quantum Finite State Automata (k-Letter QFA), 1-Way Multihead Quantum Finite State Automaton (1QFA(k)), 1-Way Deterministic 2-Head Finite State Automaton (1DFA((2)), 1-Way Reversible Multihead Finite State Automaton (1RMFA(k))

  JOURNAL NAME: Applied Mathematics, Vol.7 No.9, May 31, 2016

  ABSTRACT: 1-way multihead quantum finite state automata (1QFA(k)) can be thought of modified version of 1-way quantum finite state automata (1QFA) and k-letter quantum finite state automata (k-letter QFA) respectively. It has been shown by Moore and Crutchfield as well as Konadacs and Watrous that 1QFA can’t accept all regular language. In this paper, we show different language recognizing capabilities of our model 1-way multihead QFAs. New results presented in this paper are the following ones: 1) We show that newly introduced 1-way 2-head quantum finite state automaton (1QFA(2)) structure can accept all unary regular languages. 2) A language which can’t be accepted by 1-way deterministic 2-head finite state automaton (1DFA((2)) can be accepted by 1QFA(2) with bounded error. 3) 1QFA(2) is more powerful than 1-way reversible 2-head finite state automaton (1RMFA(2)) with respect to recognition of language.