English
Related papers

Related papers: Generalised state spaces and non-locality in fault…

200 papers

The interaction with the environment is one of the main obstacles to be circumvented in practical implementations of quantum information tasks. The use of local unitaries, while not changing the initial entanglement present in a given…

Entanglement plays an indispensable role in numerous quantum information and quantum computation tasks, underscoring the need for efficiently verifying entangled states. In recent years, quantum state verification has received increasing…

Quantum Physics · Physics 2025-12-15 Lan Zhang , Yinfei Li , Ye-Chao Liu , Jiangwei Shang

We describe a resource-efficient approach to studying many-body quantum states on noisy, intermediate-scale quantum devices. We employ a sequential generation model that allows us to bound the range of correlations in the resulting…

Quantum Physics · Physics 2021-03-05 Johannes Borregaard , Matthias Christandl , Daniel Stilck França

While quantum speed-up in solving certain decision problems by a fault-tolerant universal quantum computer has been promised, a timely research interest includes how far one can reduce the resource requirement to demonstrate a provable…

Quantum Physics · Physics 2018-01-01 Jacob Miller , Stephen Sanders , Akimasa Miyake

Entanglement depth quantifies how many qubits share genuine multipartite entanglement, but certification typically relies on tailored witnesses or full tomography, both of which scale poorly with system size. We recast entanglement-depth…

Quantum Physics · Physics 2025-12-16 Marcin Płodzień

Entanglement-based quantum networks exhibit a unique flexibility in the choice of entangled resource states that are then locally manipulated by the nodes to fulfill any request in the network. Furthermore, this manipulation is not uniquely…

Quantum Physics · Physics 2025-02-04 Maria Flors Mor-Ruiz , Julius Wallnöfer , Wolfgang Dür

Distributed quantum computing offers a promising approach to scaling quantum devices by networking multiple quantum processors. We present a quantum state tomography protocol tailored for distributed quantum computers that avoids assuming…

Quantum Physics · Physics 2026-04-27 Hans Mättig-Vásquez , Aldo Delgado , Luciano Pereira

Quantum entanglement and nonlocality are inequivalent notions: There exist entangled states that nevertheless admit local-realistic interpretations. This paper studies a special class of local-hidden-variable theories, in which the linear…

Quantum Physics · Physics 2017-11-17 Bin Yan

Measurement based quantum computation (MBQC) is an effective paradigm for universal quantum computation. In this scheme, the universal set of quantum gates are realized by only local measurements on the prior prepared cluster states. The…

Quantum Physics · Physics 2013-11-26 Ding Zhong , Jian Wang , Ning Dai , Liang-Zhu Mu , Heng Fan

Increasingly sophisticated programmable quantum simulators and quantum computers are opening unprecedented opportunities for exploring and exploiting the properties of highly entangled complex quantum systems. The complexity of large…

This paper presents a general method for producing randomly perturbed density operators subject to different sets of constraints. The perturbed density operators are a specified "distance" away from the state described by the original…

Quantum Physics · Physics 2024-06-10 J. A. Montanez-Barrera , R. T. Holladay , G. P. Beretta , Michael R. von Spakovsky

Investigating a class of models that is familiar in studies of cellular automata, we find that quantum operators can be employed to describe their long distance behavior. These operators span a Hilbert space that appears to turn such a…

Quantum Physics · Physics 2009-08-25 Gerard 't Hooft

Quantum entanglement is usually revealed via a well aligned, carefully chosen set of measurements. Yet, under a number of experimental conditions, for example in communication within multiparty quantum networks, noise along the channels or…

We show that universal quantum computation can be achieved in the standard pure-state circuit model while, at any time, the entanglement entropy of all bipartitions is small---even tending to zero with growing system size. The result is…

Quantum Physics · Physics 2013-04-11 Maarten Van den Nest

Recently, several claims have been made that certain fundamental problems of distributed computing, including Leader Election and Distributed Consensus, begin to admit feasible and efficient solutions when the model of distributed…

Quantum Physics · Physics 2009-03-09 Cyril Gavoille , Adrian Kosowski , Marcin Markiewicz

Despite the exponential overhead to describe general multi-qubit quantum states and processes, efficient methods for certain state families and operations have been developed and utilised. The stabilizer formalism and the Gottesman-Knill…

Quantum Physics · Physics 2023-05-08 Maria Flors Mor-Ruiz , Wolfgang Dür

Quantum metrology allows for a huge boost in the precision of parameters estimation. However, it seems to be extremely sensitive on the noise. Bound entangled states are states with large amount of noise what makes them unusable for almost…

Quantum Physics · Physics 2015-12-09 L. Czekaj , A. Przysiezna , M. Horodecki , P. Horodecki

Quantum simulation is a central application of near-term quantum devices, pursued in both analog and digital architectures. A key challenge for both paradigms is the effect of imperfections and noise on predictive power. In this work, we…

Quantum Physics · Physics 2026-05-05 Jayant Rao , Jens Eisert , Tommaso Guaita

We propose a scheme for fault-tolerant long-range entanglement generation at the ends of a rectangular array of qubits of length $R$ and a square cross section of size $d\times d$ with $d=O(\log R)$. Up to an efficiently computable Pauli…

Quantum Physics · Physics 2022-09-21 Shin Ho Choe , Robert Koenig

Nonlocality and its connections to entanglement are fundamental features of quantum mechanics that have found numerous applications in quantum information science. A set of correlations is said to be nonlocal if it cannot be reproduced by…

Quantum Physics · Physics 2023-11-30 Khashayar Barooti , Alexandru Gheorghiu , Grzegorz Głuch , Marc-Olivier Renou