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Related papers: Two-way Quantum One-counter Automata

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In this work, we develop a method to use Quantum- Dot Cellular Automata (QCA) for universal quantum computing. This method is based conceptually on refocusing in NMR systems. We show how an array of QCA cells can be used for isolated single…

Quantum Physics · Physics 2024-05-28 Seyed Arash Sheikholeslam , Konrad Walus

This paper develops a model of quantum behavior that is intended to support the abstract yet accurate design and functional verification of quantum communication protocols. The work is motivated by the need for conceptual tools for the…

Quantum Physics · Physics 2024-02-22 Liyi Li , Le Chang , Rance Cleaveland , Mingwei Zhu , Xiaodi Wu

The question of the state-size cost for simulation of two-way nondeterministic automata (2NFAs) by two-way deterministic automata (2DFAs) was raised in 1978 and, despite many attempts, it is still open. Subsequently, the problem was…

Formal Languages and Automata Theory · Computer Science 2011-10-07 Viliam Geffert , Bruno Guillon , Giovanni Pighizzini

Quantum phases of matter are resources for notions of quantum computation. In this work, we establish a new link between concepts of quantum information theory and condensed matter physics by presenting a unified understanding of…

One-way functions are a very important notion in the field of classical cryptography. Most examples of such functions, including factoring, discrete log or the RSA function, can be, however, inverted with the help of a quantum computer. In…

Quantum Physics · Physics 2007-05-23 Elham Kashefi , Iordanis Kerenidis

We consider communication between two parties using a bipartite quantum operation, which constitutes the most general quantum mechanical model of two-party communication. We primarily focus on the simultaneous forward and backward…

Quantum Physics · Physics 2014-11-18 Andrew M. Childs , Debbie W. Leung , Hoi-Kwong Lo

This paper introduces deterministic weighted real-time one-counter automaton (DWROCA). A DWROCA is a deterministic real-time one-counter automaton whose transitions are assigned a weight from a field. Two DWROCAs are equivalent if every…

Formal Languages and Automata Theory · Computer Science 2024-11-19 Prince Mathew , Vincent Penelle , Prakash Saivasan , A. V. Sreejith

Quantum walks on lattices can give rise to one-particle relativistic wave equations in the long-wavelength limit. In going to multiple particles, quantum cellular automata (QCA) are natural generalizations of quantum walks. In one spatial…

Quantum Physics · Physics 2021-01-04 Todd A. Brun , Leonard Mlodinow

The present paper introduces and studies an alternative concept of two-way finite automata called input-erasing two-way finite automata. Like the original model, these new automata can also move the reading head freely left or right on the…

Formal Languages and Automata Theory · Computer Science 2025-04-03 Alexander Meduna , Dominik Nejedlý , Zbyněk Křivka

In this paper we present the two-state vector formalism of quantum mechanics. It is a time-symmetrized approach to standard quantum theory particularly helpful for the analysis of experiments performed on pre- and post-selected ensembles.…

Quantum Physics · Physics 2007-06-10 Yakir Aharonov , Lev Vaidman

We introduce Superstate Quantum Mechanics (SQM), a theory that considers states in Hilbert space subject to multiple quadratic constraints, with ``energy'' also expressed as a quadratic function of these states. Traditional quantum…

We study the influence of the dimension of cellular automata (CA) for real time language recognition of one-dimensional languages with parallel input. Specifically, we focus on the question of determining whether every language that can be…

Formal Languages and Automata Theory · Computer Science 2016-10-04 Anaël Grandjean , Victor Poupet

One-way quantum computing achieves the full power of quantum computation by performing single particle measurements on some many-body entangled state, known as the resource state. As single particle measurements are relatively easy to…

Quantum Physics · Physics 2013-05-29 Jianxin Chen , Xie Chen , Runyao Duan , Zhengfeng Ji , Bei Zeng

When used as verifiers in Arthur-Merlin systems, two-way quantum finite automata can verify membership in all languages with bounded error with double-exponential expected running time, which cannot be achieved by their classical…

Formal Languages and Automata Theory · Computer Science 2025-02-19 Zeyu Chen , Abuzer Yakaryılmaz

We find an application in quantum finite automata for the ideas and results of [JL21] and [JL22]. We reformulate quantum finite automata with multiple-time measurements using the algebraic notion of near-ring. This gives a unified…

Formal Languages and Automata Theory · Computer Science 2022-04-21 George Jeffreys , Siu-Cheong Lau

We investigate the density classification task (DCT) -- determining the majority bit in a one-dimensional binary lattice -- within a quantum cellular automaton (CA) framework. While there is no one-dimensional two-state, radius $r \geq 1$,…

Quantum Physics · Physics 2025-10-09 Pedro C. S. Costa , Yuval R. Sanders , Pedro Paulo Balbi , Gavin K. Brennen

We present a simple construction of quantum automata which achieve an exponential advantage over classical finite automata. Our automata use \frac{4}{\epsilon} \log 2p + O(1) states to recognize a language that requires p states…

Quantum Physics · Physics 2008-05-13 Andris Ambainis , Nikolajs Nahimovs

We introduce Merlin-Arthur (MA) automata where Merlin provides a certificate at the beginning of computation and it is scanned by Arthur before reading the input. We define Merlin-Arthur deterministic, probabilistic, and quantum finite…

Formal Languages and Automata Theory · Computer Science 2024-07-19 Abuzer Yakaryılmaz

We propose a physical realization of quantum cellular automata (QCA) using arrays of ultracold atoms excited to Rydberg states. The key ingredient is the use of programmable multifrequency couplings which generalize the Rydberg blockade and…

Quantum Physics · Physics 2020-02-25 T. M. Wintermantel , Y. Wang , G. Lochead , S. Shevate , G. K. Brennen , S. Whitlock

Processes such as quantum computation, or the evolution of quantum cellular automata are typically described by a unitary operation implemented by an external observer. In particular, an interaction is generally turned on for a precise…

Quantum Physics · Physics 2018-11-06 Mischa P. Woods , Ralph Silva , Jonathan Oppenheim