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The rapid development of machine learning and quantum computing has placed quantum machine learning at the forefront of research. However, existing quantum machine learning algorithms based on quantum variational algorithms face challenges…

Quantum Physics · Physics 2025-08-22 Da Zhang , Xin Li , Yibin Guo , Haifeng Yu , Yirong Jin , Zhang-Qi Yin

Quantum computing leverages the principles of quantum mechanics to perform computations far beyond the capabilities of classical systems, particularly in fields such as cryptography and optimization. However, current quantum programming…

Programming Languages · Computer Science 2025-03-18 Simone Faro , Francesco Pio Marino , Gabriele Messina

We establish a direct connection between spread complexity and quantum circuit complexity by demonstrating that spread complexity emerges as a limiting case of a circuit complexity framework built from two fundamental operations:…

High Energy Physics - Theory · Physics 2026-05-19 Cameron Beetar , Eric L Graef , Jeff Murugan , Horatiu Nastase , Hendrik J R Van Zyl

This paper summarizes a research program that has been underway for a decade. The objective is to find a fast and accurate scheme for solving quantum problems which does not involve a Monte Carlo algorithm. We use an alternative strategy…

High Energy Physics - Phenomenology · Physics 2007-05-23 Carl M. Bender , Lawrence R. Mead , Kimball A. Milton

We establish improved complexity estimates of quantum algorithms for linear dissipative ordinary differential equations (ODEs) and show that the time dependence can be fast-forwarded to be sub-linear. Specifically, we show that a quantum…

Quantum Physics · Physics 2026-01-28 Dong An , Akwum Onwunta , Gengzhi Yang

Quantum computation with quantum data that can traverse closed timelike curves represents a new physical model of computation. We argue that a model of quantum computation in the presence of closed timelike curves can be formulated which…

Quantum Physics · Physics 2008-11-26 Dave Bacon

Refactoring is a crucial technique for improving the efficiency and maintainability of software by restructuring its internal design while preserving its external behavior. While classical programs have benefited from various refactoring…

Software Engineering · Computer Science 2023-06-21 Jianjun Zhao

Quantum computing promises to enhance machine learning and artificial intelligence. Different quantum algorithms have been proposed to improve a wide spectrum of machine learning tasks. Yet, recent theoretical works show that, similar to…

Quantum query complexity is known to be characterized by the so-called quantum adversary bound. While this result has been proved in the standard discrete-time model of quantum computation, it also holds for continuous-time (or…

Quantum Physics · Physics 2015-07-01 Mathieu Brandeho , Jérémie Roland

Quantum complexity measures the difficulty of obtaining a given state starting from a typically unentangled state. In this work, we show that complexity, when defined through the minimization of a Riemannian cost functional over the…

Quantum Physics · Physics 2025-06-05 Nadir Samos Sáenz de Buruaga

Quantum computing comes with the potential to push computational boundaries in various domains including, e.g., cryptography, simulation, optimization, and machine learning. Exploiting the principles of quantum mechanics, new algorithms can…

Systems and Control · Electrical Eng. & Systems 2025-12-23 Julian Berberich , Robert L. Kosut , Thomas Schulte-Herbrüggen

Overcoming the influence of noise and imperfections is a major challenge in quantum computing. Here, we present an approach based on applying a desired unitary computation in superposition between the system of interest and some auxiliary…

We establish a lower bound concerning the computational complexity of Grover's algorithms on fractal networks. This bound provides general predictions for the quantum advantage gained for searching unstructured lists. It yields a…

Statistical Mechanics · Physics 2018-07-19 Stefan Boettcher , Shanshan Li , Tharso D. Fernandes , Renato Portugal

Quantum tomography is the main method used to assess the quality of quantum information processing devices, but its complexity presents a major obstacle for the characterization of even moderately large systems. The number of experimental…

Quantum Physics · Physics 2015-03-19 Marcus P. da Silva , Olivier Landon-Cardinal , David Poulin

In this paper, the space complexity of nonuniform quantum computations is investigated. The model chosen for this are quantum branching programs, which provide a graphic description of sequential quantum algorithms. In the first part of the…

Quantum Physics · Physics 2007-05-23 M. Sauerhoff , D. Sieling

A test of quantumness is a protocol that allows a classical verifier to certify (only) that a prover is not classical. We show that tests of quantumness that follow a certain template, which captures recent proposals such as (Kalai et al.,…

Quantum computation is one of the most promising new paradigms for the simulation of physical systems composed of electrons and atomic nuclei, with applications in chemistry, solid-state physics, materials science, and molecular biology.…

Quantum Physics · Physics 2024-11-05 Jakob Günther , Alberto Baiardi , Markus Reiher , Matthias Christandl

Quantum phenomena have the potential to speed up the solution of hard optimization problems. For example quantum annealing, based on the quantum tunneling effect, has recently been shown to scale exponentially better with system size as…

Quantum Physics · Physics 2017-04-27 Simon E. Nigg , Niels Loerch , Rakesh P. Tiwari

Quantum algorithms for graph problems are considered, both in the adjacency matrix model and in an adjacency list-like array model. We give almost tight lower and upper bounds for the bounded error quantum query complexity of Connectivity,…

Quantum Physics · Physics 2016-12-30 Christoph Durr , Mark Heiligman , Peter Hoyer , Mehdi Mhalla

Machine learning algorithms perform well on identifying patterns in many different datasets due to their versatility. However, as one increases the size of the dataset, the computation time for training and using these statistical models…

Quantum Physics · Physics 2024-09-19 Abhijat Sarma , Rupak Chatterjee , Kaitlin Gili , Ting Yu