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Related papers: Multivariate Fidelities

200 papers

We discuss quantum fidelity decay of classically regular dynamics, in particular for an important special case of a vanishing time averaged perturbation operator, i.e. vanishing expectation values of the perturbation in the eigenbasis of…

Quantum Physics · Physics 2009-11-10 Tomaz Prosen , Marko Znidaric

The Eastin-Knill theorem is a central result of quantum error correction theory and states that a quantum code cannot correct errors exactly, possess continuous symmetries, and implement a universal set of gates transversely. As a way to…

Quantum Physics · Physics 2023-03-28 Guilherme Fiusa , Diogo O. Soares-Pinto , Diego Paiva Pires

In this paper we review our recent work on the theoretical approach to quantum Loschmidt echoes, i.e. various properties of the so called echo dynamics -- the composition of forward and backward time evolutions generated by two slightly…

Quantum Physics · Physics 2009-11-10 Tomaz Prosen , Thomas H. Seligman , Marko Znidaric

Unitarity is a cornerstone of quantum theory, ensuring the conservation of probability and information. Although non-Hermitian Hamiltonians are typically associated with open or dissipative systems, pseudo-Hermitian quantum mechanics shows…

High Energy Physics - Theory · Physics 2025-11-03 Ruifeng Leng , Cheng-Yang Lee , Siyi Zhou

As quantum devices continue to scale, distributed quantum computing emerges as a promising strategy for executing large-scale tasks across modular quantum processors. A central challenge in this paradigm is verifying the correctness of…

Recently quantum states discrimination has been frequently studied. In this paper we study them from the other way round, the likeness of two quantum states. The fidelity is used to describe the likeness of two quantum states. Then we…

Quantum Physics · Physics 2009-11-07 Fei Xue , Jiangfeng Du , Xianyi Zhou , Rongdian Han , Jihui Wu

When a system undergoes a quantum phase transition, the ground-state wave-function shows a change of nature, which can be monitored using the fidelity concept. We introduce two Quantum Monte Carlo schemes that allow the computation of…

Strongly Correlated Electrons · Physics 2009-10-21 David Schwandt , Fabien Alet , Sylvain Capponi

Estimating the difference between quantum data is crucial in quantum computing. However, as typical characterizations of quantum data similarity, the trace distance and quantum fidelity are believed to be exponentially-hard to evaluate in…

Quantum Physics · Physics 2021-12-28 Ranyiliu Chen , Zhixin Song , Xuanqiang Zhao , Xin Wang

Fawzi and Renner [Commun. Math. Phys. 340(2):575, 2015] recently established a lower bound on the conditional quantum mutual information (CQMI) of tripartite quantum states $ABC$ in terms of the fidelity of recovery (FoR), i.e. the maximal…

Quantum Physics · Physics 2016-03-30 Mario Berta , Marco Tomamichel

In system analysis and design optimization, multiple computational models are typically available to represent a given physical system. These models can be broadly classified as high-fidelity models, which provide highly accurate…

Machine Learning · Computer Science 2024-11-01 Ruda Zhang , Negin Alemazkoor

Squashed entanglement is a measure for the entanglement of bipartite quantum states. In this paper we present a lower bound for squashed entanglement in terms of a distance to the set of separable states. This implies that squashed…

Quantum Physics · Physics 2012-07-23 Fernando G. S. L. Brandao , Matthias Christandl , Jon Yard

The progress in quantum operations of continuous-variable (CV) schemes can be reduced to that in CV quantum teleportation. The fidelity of quantum teleportation of an optical setup is limited by the finite degree of quantum correlation…

Quantum Physics · Physics 2008-02-27 Mitsuyoshi Yukawa , Hugo Benichi , Akira Furusawa

We relate gate fidelities of experimentally realized quantum operations to the broadcasting property of their ideal operations, and show that the more parties a given quantum operation can broadcast to, the higher gate fidelities of its…

Quantum Physics · Physics 2011-06-30 Hyang-Tag Lim , Young-Sik Ra , Yong-Su Kim , Yoon-Ho Kim , Joonwoo Bae

We analyze the average fidelity (say, F) and the fidelity deviation (say, D) in noisy-channel quantum teleportation. Here, F represents how well teleportation is performed on average and D quantifies whether the teleportation is performed…

Quantum Physics · Physics 2021-03-23 WooYeong Song , Junghee Ryu , Kyunghyun Baek , Jeongho Bang

We define a general formulation of quantum PCPs, which captures adaptivity and multiple unentangled provers, and give a detailed construction of the quantum reduction to a local Hamiltonian with a constant promise gap. The reduction turns…

Quantum Physics · Physics 2025-07-16 Harry Buhrman , Jonas Helsen , Jordi Weggemans

It is a fundamental problem to decide how many copies of an unknown mixed quantum state are necessary and sufficient to determine the state. Previously, it was known only that estimating states to error $\epsilon$ in trace distance required…

Quantum Physics · Physics 2017-09-01 Jeongwan Haah , Aram W. Harrow , Zhengfeng Ji , Xiaodi Wu , Nengkun Yu

In this paper we extend our recent results for quantum teleportation of single qubit pure information state using non-maximally entangled pure state resource [Quantum Inf Process, 11 (2012) 1251] to the case of a general mixed information…

Quantum Physics · Physics 2013-05-21 Hari Prakash , Vikram Verma

Two measures of sensitivity to eavesdropping for alphabets of quantum states were recently introduced by Fuchs and Sasaki in quant-ph/0302092. These are the accessible fidelity and quantumness. In this paper we prove an important property…

Quantum Physics · Physics 2007-05-23 K. M. R. Audenaert , C. A. Fuchs , C. King , A. Winter

A quantum ensemble $\{(p_x, \rho_x)\}$ is a set of quantum states each occurring randomly with a given probability. Quantum ensembles are necessary to describe situations with incomplete a priori information, such as the output of a…

Quantum Physics · Physics 2009-03-30 Ognyan Oreshkov , John Calsamiglia

Motivated by the growing importance of fidelity in quantum critical phenomena, we establish a general relation between fidelity and structure factor of the driving term in a Hamiltonian through a newly introduced concept: fidelity…

Quantum Physics · Physics 2009-11-13 Wen-Long You , Ying-Wai Li , Shi-Jian Gu