On the space-efficiency of 1-way quantum finite automata
نویسندگان
چکیده
We exhibit a family {Ln} of finite regular languages such that any 1-way quantum finite automaton (QFA) accepting Ln with probability 1 2 + ǫ (for any constant ǫ > 0) must have 2 Ω(n/ logn) states. On the other hand, each language Ln can be recognized by a deterministic finite automaton (DFA) of size O(n). This is in immediate contrast to the result of [1] which shows that for some regular languages, 1-way QFAs can be exponentially more space-efficient as compared to DFAs.
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