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1-way quantum finite automata: strengths, weaknesses and generalizations

Quantum Physics · Submitted 25 Feb 1998

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim Namely, we construct a 1-way QFA which is exponentially smaller than any equivalent classical (even randomized) finite automaton.

how it is stated · asserted 1.00 read the record →

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arXiv IDquant-ph/9802062 (version 3)
Pith IDKVNULRRX, Pith's permanent record of this paper and its review
CitationA. Ambainis, R. Freivalds. "1-way quantum finite automata: strengths, weaknesses and generalizations." arXiv:quant-ph/9802062 (1998). https://pith.science/paper/KVNULRRX
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What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.44 · human participants 0.01 · controlled comparison 0.51 · randomized assignment 0.03 · states quantitative result 0.96 · compares with prior results 0.92 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v3. Results and the main claim are underlined; .

We study 1-way quantum finite automata (QFAs). First, we compare them with their classical counterparts. We show that, if an automaton is required to give the correct answer with a large probability (over 0.98), then the power of 1-way QFAs is equal to the power of 1-way reversible automata. However, quantum automata giving the correct answer with smaller probabilities are more powerful than reversible automata. Second, we show that 1-way QFAs can be very space-efficient. Namely, we construct a 1-way QFA which is exponentially smaller than any equivalent classical (even randomized) finite automaton. This construction may be useful for design of other space-efficient quantum algorithms. Third, we consider several generalizations of 1-way QFAs. Here, our goal is to find a model which is more powerful than 1-way QFAs keeping the quantum part as simple as possible.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 We study 1-way quantum finite automata (QFAs). contribution 0.65 0.57 0.02 asserted 0.54
s1 First, we compare them with their classical counterparts. contribution 0.72 0.82 0.02 unclear 0.50
s2 We show that, if an automaton is required to give the correct answer with a large probability (over 0.98), then the power of 1-way QFAs is equal to the power of 1-way reversible automata. result 1.00 0.92 0.29 asserted 1.00
s3 However, quantum automata giving the correct answer with smaller probabilities are more powerful than reversible automata. result 1.00 0.88 0.19 asserted 1.00
s4 Second, we show that 1-way QFAs can be very space-efficient. result 0.76 0.82 0.12 asserted 0.86
s5 Namely, we construct a 1-way QFA which is exponentially smaller than any equivalent classical (even randomized) finite automaton. result 0.84 0.96 0.21 asserted 1.00
s6 This construction may be useful for design of other space-efficient quantum algorithms. interpretation 0.79 0.30 0.05 hedged possibility 1.00
s7 Third, we consider several generalizations of 1-way QFAs. contribution 0.98 0.88 0.03 asserted 0.78
s8 Here, our goal is to find a model which is more powerful than 1-way QFAs keeping the quantum part as simple as possible. contribution 0.65 0.54 0.05 asserted 0.62

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from proof or derivation 1.00.

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Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

The paper
Original abstract

We study 1-way quantum finite automata (QFAs). First, we compare them with their classical counterparts. We show that, if an automaton is required to give the correct answer with a large probability (over 0.98), then the power of 1-way QFAs is equal to the power of 1-way reversible automata. However, quantum automata giving the correct answer with smaller probabilities are more powerful than reversible automata. Second, we show that 1-way QFAs can be very space-efficient. Namely, we construct a 1-way QFA which is exponentially smaller than any equivalent classical (even randomized) finite automaton. This construction may be useful for design of other space-efficient quantum algorithms. Third, we consider several generalizations of 1-way QFAs. Here, our goal is to find a model which is more powerful than 1-way QFAs keeping the quantum part as simple as possible.

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References
How the literature uses it

8 arXiv papers cite this in 13 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 10 sentences without a confident label

Uses its method or tool 1 paper
  • The algorithm takes $X_1$ and obtains a value of the function $v_1=EQ(X_1)$ using quantum fingerprinting method presented in [ref] , [ref] .

    Quantum Online Algorithms with Respect to Space Complexity · Polylogarithmic Space Complexity Separation between Quantum and Deterministic Online Algorithms with Polylogarithmic Mem · 1.00

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