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Related papers: Improved constructions of quantum automata

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Estimating observable expectation values in eigenstates of quantum systems has a broad range of applications and is an area where early fault-tolerant quantum computers may provide practical quantum advantage. We develop a hybrid…

Quantum Physics · Physics 2026-03-03 Bence Bakó , Tenzan Araki , Bálint Koczor

The quantum Fourier transform (QFT) plays an important role in many known quantum algorithms such as Shor's algorithm for prime factorisation. In this paper we show that the QFT algorithm can, on a restricted set of input states, be…

Quantum Physics · Physics 2020-01-27 Alastair A. Abbott

We study the recognition of R-trivial idempotent (R1) languages by various models of "decide-and-halt" quantum finite automata (QFA) and probabilistic reversible automata (DH-PRA). We introduce bistochastic QFA (MM-BQFA), a model which…

Formal Languages and Automata Theory · Computer Science 2011-09-07 Marats Golovkins , Maksim Kravtsev , Vasilijs Kravcevs

The initialization of quantum states or Quantum State Preparation (QSP) is a basic subroutine in quantum algorithms. In the worst case, general QSP algorithms are expensive due to the application of multi-controlled gates required to build…

Is quantum mechanics about 'states'? Or is it basically another kind of probability theory? It is argued that the elementary formalism of quantum mechanics operates as a well-justified alternative to 'classical' instantiations of a…

Quantum Physics · Physics 2014-10-28 Jean-Michel Delhotel

We describe a uniform construction for converting $\omega$-automata with arbitrary acceptance conditions (based on the notion of infinity sets i.e. the set of states visited infinitely often in a run of the automaton) to equivalent…

Formal Languages and Automata Theory · Computer Science 2015-03-17 Hrishikesh Karmarkar , Supratik Chakraborty

In this work we construct an automaton for the commutative closure of a given regular group language. The number of states of the resulting automaton is bounded by the number of states of the original automaton, raised to the power of the…

Formal Languages and Automata Theory · Computer Science 2020-08-14 Stefan Hoffmann

Quantum computation based on quantum cellular automata (QCA) can greatly reduce the control and precision necessary for experimental implementations of quantum information processing. A QCA system consists of a few species of qubits in…

Quantum Physics · Physics 2009-11-10 Yaakov S. Weinstein , C. Stephen Hellberg

Quantitative automata are useful representations for numerous applications, including modeling probability distributions over sequences to Markov chains and reward machines. Actively learning such automata typically occurs using explicitly…

Formal Languages and Automata Theory · Computer Science 2024-11-19 Eric Hsiung , Swarat Chaudhuri , Joydeep Biswas

Quantum computing promises the ability to compute properties of quantum systems exponentially faster than classical computers. Quantum advantage is achieved when a practical problem is solved more efficiently on a quantum computer than on a…

Quantum Physics · Physics 2025-12-03 William A. Simon , Peter J. Love

We present logically based methods for constructing XP and FPT graph algorithms, parametrized by tree-width or clique-width. We will use fly-automata introduced in a previous article. They make possible to check properties that are not…

Logic in Computer Science · Computer Science 2015-12-21 Bruno Courcelle , Irène Durand

We construct a classical oracle relative to which $\mathsf{P} = \mathsf{NP}$ yet single-copy secure pseudorandom quantum states exist. In the language of Impagliazzo's five worlds, this is a construction of pseudorandom states in…

Quantum Physics · Physics 2025-09-18 William Kretschmer , Luowen Qian , Makrand Sinha , Avishay Tal

In this paper, we describe a new method for constructing minimal, deterministic, acyclic finite-state automata from a set of strings. Traditional methods consist of two phases: the first to construct a trie, the second one to minimize it.…

Computation and Language · Computer Science 2007-05-23 Jan Daciuk , Stoyan Mihov , Bruce Watson , Richard Watson

We investigate the computational power of affine automata (AfAs) introduced in [4]. In particular, we present a simpler proof for how to change the cutpoint for any affine language and a method how to reduce error in bounded error case.…

Formal Languages and Automata Theory · Computer Science 2018-06-19 Mika Hirvensalo , Etienne Moutot , Abuzer Yakaryılmaz

One of the properties of Kondacs-Watrous model of quantum finite automata (QFA) is that the probability of the correct answer for a QFA cannot be amplified arbitrarily. In this paper, we determine the maximum probabilities achieved by QFAs…

Quantum Physics · Physics 2007-05-23 Andris Ambainis , Arnolds Kikusts

Automata over infinite words, also known as omega-automata, play a key role in the verification and synthesis of reactive systems. The spectrum of omega-automata is defined by two characteristics: the acceptance condition (e.g. B\"uchi or…

Formal Languages and Automata Theory · Computer Science 2021-01-01 Rayna Dimitrova , Bernd Finkbeiner , Hazem Torfah

We consider the possibility of encoding m classical bits into much fewer n quantum bits so that an arbitrary bit from the original m bits can be recovered with a good probability, and we show that non-trivial quantum encodings exist that…

Quantum Physics · Physics 2019-08-17 Andris Ambainis , Ashwin Nayak , Amnon Ta-Shma , Umesh Vazirani

One of the distinct features of quantum mechanics is that the probability amplitude can have both positive and negative signs, which has no classical counterpart as the classical probability must be positive. Consequently, one possible way…

Quantum Physics · Physics 2022-04-28 Vicky Choi

This paper develops an assume-guarantee (AG) framework for the compositional verification of probabilistic automata (PAs) with uncertain transition probabilities. We study parametric probabilistic automata (pPAs), where probabilities are…

Logic in Computer Science · Computer Science 2026-04-01 Hannah Mertens , Tim Quatmann , Joost-Pieter Katoen

Many sequences of $p$-adic integers project modulo $p^\alpha$ to $p$-automatic sequences for every $\alpha \geq 0$. Examples include algebraic sequences of integers, which satisfy this property for every prime $p$, and some cocycle…

Dynamical Systems · Mathematics 2017-05-02 Eric Rowland , Reem Yassawi