English
Related papers

Related papers: Quantum subroutine problem and the robustness of q…

200 papers

With a combination of the quantum repeater and the cluster state approaches, we show that efficient quantum computation can be constructed even if all the entangling quantum gates only succeed with an arbitrarily small probability $p$. The…

Quantum Physics · Physics 2009-11-11 L. -M. Duan , R. Raussendorf

The computational complexity of simulating the dynamics of physical quantum systems is a central question at the interface of quantum physics and computer science. In this work, we address this question for the simulation of exponentially…

Quantum Physics · Physics 2026-04-15 Lilith Zschetzsche , Refik Mansuroglu , Norbert Schuch

In the standard oracle model, an oracle efficiently evaluates an unknown classical function independent of the quantum algorithm itself. Quantum algorithms have a complex interrelationship to their oracles; for example the possibility of…

Quantum Physics · Physics 2022-06-29 Cica Gustiani , David P. DiVincenzo

The universality of a quantum neural network refers to its ability to approximate arbitrary functions and is a theoretical guarantee for its effectiveness. A non-universal neural network could fail in completing the machine learning task.…

Quantum Physics · Physics 2023-06-27 Xiaokai Hou , Guanyu Zhou , Qingyu Li , Shan Jin , Xiaoting Wang

A critical question for the field of quantum computing in the near future is whether quantum devices without error correction can perform a well-defined computational task beyond the capabilities of state-of-the-art classical computers,…

We consider the power of various quantum complexity classes with the restriction that states and operators are defined over a real, rather than complex, Hilbert space. It is well know that a quantum circuit over the complex numbers can be…

Quantum Physics · Physics 2015-10-13 Matthew McKague

This paper considers the problem of robust stability for a class of uncertain quantum systems subject to unknown perturbations in the system coupling operator. A general stability result is given for a class of perturbations to the system…

Quantum Physics · Physics 2012-08-31 Ian R. Petersen , Valery Ugrinovskii , Matthew R. James

Software testing is a critical component of the classical software development lifecycle, and this principle is expected to hold true for quantum software as it evolves toward large-scale production and adherence to industry standards.…

We discuss a model for quantum computing with initially mixed states. Although such a computer is known to be less powerful than a quantum computer operating with pure (entangled) states, it may efficiently solve some problems for which no…

Quantum Physics · Physics 2015-03-17 Michael Siomau , Stephan Fritzsche

Algorithms with unitary oracles can be nested, which makes them extremely versatile. An example is the phase estimation algorithm used in many candidate algorithms for quantum speed-up. The search for new quantum algorithms benefits from…

Quantum Physics · Physics 2024-04-01 Zuzana Gavorová , Matan Seidel , Yonathan Touati

We extend molecular bootstrap embedding to make it appropriate for implementation on a quantum computer. This enables solution of the electronic structure problem of a large molecule as an optimization problem for a composite Lagrangian…

It is believed that random quantum circuits are difficult to simulate classically. These have been used to demonstrate quantum supremacy: the execution of a computational task on a quantum computer that is infeasible for any classical…

Theoretical computer scientists have been debating the role of oracles since the 1970's. This paper illustrates both that oracles can give us nontrivial insights about the barrier problems in circuit complexity, and that they need not…

Computational Complexity · Computer Science 2007-05-23 Scott Aaronson

Quantum query complexity studies the number of queries needed to learn some property of a black box. A closely related question is how well an algorithm can succeed with this learning task using only a fixed number of queries. In this work,…

The power of quantum computers is still somewhat speculative. While they are certainly faster than classical ones at some tasks, the class of problems they can efficiently solve has not been mapped definitively onto known classical…

Quantum Physics · Physics 2020-07-09 N. H. Nguyen , E. C. Behrman , M. A. Moustafa , J. E. Steck

Many of the envisioned use-cases for quantum computers involve optimisation processes. While there are many algorithmic primitives to perform the required calculations, all eventually lead to quantum gates operating on quantum bits, with an…

Quantum Physics · Physics 2026-03-26 Lukas Schmidbauer , Elisabeth Lobe , Ina Schaefer , Wolfgang Mauerer

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

Optimization of circuits is an essential task for both quantum and classical computers to improve their efficiency. In contrast, classical logic optimization is known to be difficult, and a lot of heuristic approaches have been developed so…

Quantum Physics · Physics 2025-05-14 Yusei Mori , Hideaki Hakoshima , Kyohei Sudo , Toshio Mori , Kosuke Mitarai , Keisuke Fujii

Errors occurring on noisy hardware pose a key challenge to reliable quantum computing. Existing techniques such as error correction, mitigation, or suppression typically separate the error handling from the algorithm analysis and design. In…

Quantum Physics · Physics 2026-01-21 Julian Berberich , Tobias Fellner , Robert L. Kosut , Christian Holm

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