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Related papers: Chain rules for quantum channels

200 papers

The chain rule for the classical relative entropy ensures that the relative entropy between probability distributions on multipartite systems can be decomposed into a sum of relative entropies of suitably chosen conditional distributions on…

Quantum Physics · Physics 2020-03-18 Kun Fang , Omar Fawzi , Renato Renner , David Sutter

We introduce a new quantum R\'enyi divergence $D^{\#}_{\alpha}$ for $\alpha \in (1,\infty)$ defined in terms of a convex optimization program. This divergence has several desirable computational and operational properties such as an…

Quantum Physics · Physics 2021-01-27 Hamza Fawzi , Omar Fawzi

We study asymmetric binary channel discrimination, for qantum channels acting on separable Hilbert spaces. We establish quantum Stein's lemma for channels for both adaptive and parallel strategies, and show that under finiteness of the…

Quantum Physics · Physics 2023-08-25 Bjarne Bergh , Jan Kochanowski , Robert Salzmann , Nilanjana Datta

We investigate the coherence of quantum channels and establish a resource theory for quantifying the coherence of quantum channels via Choi matrix. To this aim, we define the incoherent channels and incoherent superchannels. This theory…

Quantum Physics · Physics 2019-11-12 Jianwei Xu

Uncertainty principle reveals the intrinsic differences between the classical and quantum worlds, which plays a significant role in quantum information theory. By using $\rho$-absolute variance, we introduce the uncertainty of quantum…

Quantum Physics · Physics 2024-07-26 Cong Xu , Wen Zhou , Qing-Hua Zhang , Shao-Ming Fei

Relative entropy is the standard measure of distinguishability in classical and quantum information theory. In the classical case, its loss under channels admits an exact chain rule, while in the quantum case only asymptotic, regularized…

Quantum Physics · Physics 2026-05-26 Giulio Gasbarri , Matt Hoogsteder-Riera

Distinguishability is fundamental to information theory and extends naturally to quantum systems. While quantum state discrimination is well understood, quantum channel discrimination remains challenging due to the dynamic nature of…

Quantum Physics · Physics 2025-07-15 Kun Fang , Gilad Gour , Xin Wang

The uncertainty relation reveals the intrinsic difference between the classical world and the quantum world. We investigate the quantum uncertainty relation of quantum channel in qubit systems. Under two general measurement bases, we first…

Quantum Physics · Physics 2024-09-02 Shi-Yun Kong , Ming-Jing Zhao , Zhi-Xi Wang , Shao-Ming Fei

We present an "uncertainty principle" for quantum channels, showing a relationship between the dimensions of the range of a channel and the range of its complement. We examine some interesting specific cases, and discuss consequences for…

Quantum Physics · Physics 2016-11-22 Jeremy Levick

Originated from the superposition principle in quantum mechanics, coherence has been extensively studied as a kind important resource in quantum information processing. We investigate the distinguishability of coherence-breaking channels…

Quantum Physics · Physics 2019-09-04 Long-Mei Yang , Tao Li , Shao-Ming Fei , Zhi-Xi Wang

Quantum channel, as the information transmitter, is an indispensable tool in quantum information theory. In this paper, we study a class of special quantum channels named the mixed-permutation channels. The properties of these channels are…

Quantum Physics · Physics 2024-01-15 Lin Zhang , Ming-Jing Zhao

By revisiting the mathematical foundation of the uncertainty relation, skew information-based uncertainty sequences are developed for any two quantum channels. A reinforced version of the Cauchy-Schwarz inequality is adopted to improve the…

Quantum Physics · Physics 2023-10-11 Xiaoli Hu , Naihong Hu , Bing Yu , Naihuan Jing

We consider the sequential quantum channel discrimination problem using adaptive and non-adaptive strategies. In this setting the number of uses of the underlying quantum channel is not fixed but a random variable that is either bounded in…

Information Theory · Computer Science 2022-10-21 Yonglong Li , Christoph Hirche , Marco Tomamichel

In this work we analyze properties of generic quantum channels in the case of large system size. We use random matrix theory and free probability to show that the distance between two independent random channels converges to a constant…

Quantum Physics · Physics 2018-07-09 Ion Nechita , Zbigniew Puchała , Łukasz Pawela , Karol Życzkowski

In the problem of quantum channel discrimination, one distinguishes between a given number of quantum channels, which is done by sending an input state through a channel and measuring the output state. This work studies applications of…

Quantum Physics · Physics 2022-09-08 Andrey Kardashin , Anna Vlasova , Anastasiia Pervishko , Dmitry Yudin , Jacob Biamonte

A quantum channel is a mapping which sends density matrices to density matrices. The estimation of quantum channels is of great importance to the field of quantum information. In this thesis two topics related to estimation of quantum…

Quantum Physics · Physics 2010-01-25 Caleb J. O'Loan

We present a systematic study of the geometric R\'enyi divergence (GRD), also known as the maximal R\'enyi divergence, from the point of view of quantum information theory. We show that this divergence, together with its extension to…

Quantum Physics · Physics 2021-10-29 Kun Fang , Hamza Fawzi

Many important properties of quantum channels are quantified by means of entropic functionals. Characteristics of such a kind are closely related to different representations of a quantum channel. In the Jamio{\l}kowski-Choi representation,…

Quantum Physics · Physics 2013-07-23 Alexey E. Rastegin

Optimal rates for achieving an information processing task are often characterized in terms of regularized information measures. In many cases of quantum tasks, we do not know how to compute such quantities. Here, we exploit the symmetries…

Quantum Physics · Physics 2023-08-25 Omar Fawzi , Ala Shayeghi , Hoang Ta

The quantum data processing inequality asserts that two quantum states become harder to distinguish when a noisy channel is applied. On the other hand, a reverse quantum data processing inequality characterizes whether distinguishability is…

Quantum Physics · Physics 2025-11-03 Paula Belzig , Li Gao , Graeme Smith , Peixue Wu
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