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Quantum samplers are believed capable of sampling efficiently from distributions that are classically hard to sample from. We consider a sampler inspired by the classical Ising model. It is nonadaptive and therefore experimentally amenable.…

Quantum Physics · Physics 2019-07-17 Theodoros Kapourniotis , Animesh Datta

We introduce and study input-driven deterministic and nondeterministic double-head pushdown automata. A double-head pushdown automaton is a slight generalization of an ordinary pushdown automaton working with two input heads that move in…

Formal Languages and Automata Theory · Computer Science 2017-08-23 Markus Holzer , Martin Kutrib , Andreas Malcher , Matthias Wendlandt

The rapid development in hardware for quantum computing and simulation has led to much interest in problems where these devices can exceed the capabilities of existing classical computers and known methods. Approaching this for problems…

Quantum Physics · Physics 2022-04-29 S. Flannigan , N. Pearson , G. H. Low , A. Buyskikh , I. Bloch , P. Zoller , M. Troyer , A. J. Daley

We review the recent quantum advantage experiments by IBM, D-Wave, and Google, focusing on cases where efficient classical simulations of the experiment were demonstrated or attempted using tensor network methods. We assess the strengths…

Quantum Physics · Physics 2026-03-27 Augustine Kshetrimayum , Saeed S. Jahromi , Sukhbinder Singh , Román Orús

In this paper, we study the problem of model-checking quantum pushdown systems from a computational complexity point of view. We arrive at the following equally important, interesting new results: We first extend the notions of the {\it…

Logic in Computer Science · Computer Science 2026-05-11 Deren Lin , Tianrong Lin

The aim of this paper is to develop novel quantum algorithms for Gaussian process quadrature methods. Gaussian process quadratures are numerical integration methods where Gaussian processes are used as functional priors for the integrands…

Computation · Statistics 2025-02-21 Cristian A. Galvis-Florez , Ahmad Farooq , Simo Särkkä

Extending the lambda-calculus with a construct for sharing, such as let expressions, enables a special representation of terms: iterated applications are decomposed by introducing sharing points in between any two of them, reducing to the…

Logic in Computer Science · Computer Science 2019-07-16 Beniamino Accattoli , Andrea Condoluci , Giulio Guerrieri , Claudio Sacerdoti Coen

We present counting reward automata-a finite state machine variant capable of modelling any reward function expressible as a formal language. Unlike previous approaches, which are limited to the expression of tasks as regular languages, our…

Artificial Intelligence · Computer Science 2024-02-20 Tristan Bester , Benjamin Rosman , Steven James , Geraud Nangue Tasse

Quantum databases open an exciting new frontier in data management by offering privacy guarantees that classical systems cannot match. Traditional engines tackle user privacy, which hides the records being queried, or data privacy, which…

Quantum Physics · Physics 2025-11-25 Giancarlo Gatti , Floris Geerts , Rihan Hai

We propose an approach to generative quantum machine learning that overcomes the fundamental scaling issues of variational quantum circuits. The core idea is to use a class of generative models based on instantaneous quantum polynomial…

Quantum Physics · Physics 2026-02-09 Erik Recio-Armengol , Shahnawaz Ahmed , Joseph Bowles

We introduce hybrid classical-quantum algorithms for problems involving a large classical data set X and a space of models Y such that a quantum computer has superposition access to Y but not X. These algorithms use data reduction…

Quantum Physics · Physics 2020-04-07 Aram W. Harrow

Consumption of magic states promotes the stabilizer model of computation to universal quantum computation. Here, we propose three different classical algorithms for simulating such universal quantum circuits, and characterize them by…

Quantum Physics · Physics 2021-03-23 James R. Seddon , Bartosz Regula , Hakop Pashayan , Yingkai Ouyang , Earl T. Campbell

Quantum computing offers the potential for superior computational capabilities, particularly for data-intensive tasks. However, the current state of quantum hardware puts heavy restrictions on input size. To address this, hybrid transfer…

We consider a class of noisy, one-dimensional quantum cellular automata that allow one to shift from unitary dynamics to completely positive maps, and investigate the notion of reversibility in such a setting. To this aim, we associate an…

Quantum Physics · Physics 2018-01-09 Federico Centrone , Camillo Tassi , Alessio Serafini , Marco Barbieri

Feedback-based quantum optimization is a quantum approach to combinatorial optimization. In this paper, we introduce the classical counterpart of feedback-based quantum optimization by using the quantum-classical correspondence of spin…

Quantum Physics · Physics 2026-05-14 Tomohiro Hattori , Takuya Hatomura

The advent of hybrid computing platforms consisting of quantum processing units integrated with conventional high-performance computing brings new opportunities for algorithm design. By strategically offloading select portions of the…

Experimenting with metastability in recording devices leads us to wonder about an interface between equations of motion and the stillness of experimental records. Here we delineate an interface between wave functions as language to describe…

Quantum Physics · Physics 2007-05-23 F. Hadi Madjid , John M. Myers

Classical correlation can be locked via quantum means--quantum data locking. With a short secret key, one can lock an exponentially large amount of information, in order to make it inaccessible to unauthorized users without the key. Quantum…

The use of advanced quantum neuron models for pattern recognition applications requires fault tolerance. Therefore, it is not yet possible to test such models on a large scale in currently available quantum processors. As an alternative, we…

Quantum Physics · Physics 2022-02-18 London A. Cavaletto , Luca Candelori , Alex Matos-Abiague

The relative power of quantum algorithms, using an adaptive access to quantum devices, versus classical post-processing methods that rely only on an initial quantum data set, remains the subject of active debate. Here, we present evidence…

Quantum Physics · Physics 2025-10-02 Oleksandr Kyriienko , Chukwudubem Umeano , Zoë Holmes