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Related papers: Bounds on skew information and local quantum uncer…

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In this paper we study the quantum generalisation of the skew divergence, which is a dissimilarity measure between distributions introduced by L. Lee in the context of natural language processing. We provide an in-depth study of the quantum…

Mathematical Physics · Physics 2015-06-15 Koenraad M. R. Audenaert

We give a bound to the precision in the estimation of a parameter in terms of the expectation value of an observable. It is an extension of the Cramer-Rao inequality and of the Heisenberg uncertainty relation, where the estimation precision…

Quantum Physics · Physics 2012-07-11 Vittorio Giovannetti , Seth Lloyd , Lorenzo Maccone

Quantum coherence is an important quantum resource which plays a pivotal role in the field of quantum information. Based on metric adjusted skew information, we define a measure of quantum uncertainty to study average coherence under…

Quantum Physics · Physics 2026-04-23 Baolong Cheng , Linlin Ye , Zhaoqi Wu

Recent findings suggest, separable states, which are otherwise of no use in entanglement dependent tasks, can also be used in information processing tasks that depend upon the discord type general non classical correlations. In this work,…

Quantum Physics · Physics 2023-07-12 Ajoy Sen , Debasis Sarkar , Amit Bhar

Information-Theoretical restrictions on the systems self-descriptions are applied to Quantum Measurements Theory. For the quantum object S measurement by information system O such restrictions are described by the restricted states…

Quantum Physics · Physics 2007-05-23 S. Mayburov

We develop an abstract way of defining linear-optics networks designed to perform quantum information tasks such as quantum gates. We will be mainly concerned with the nonlinear sign shift gate, but it will become obvious that all other…

Quantum Physics · Physics 2009-11-10 Stefan Scheel , Norbert Luetkenhaus

In this work, we consider decoupling a bipartite quantum state via a general quantum channel. We propose a joint state-channel decoupling approach to obtain a one-shot error exponent bound without smoothing, in which trace distance is used…

Quantum Physics · Physics 2024-09-24 Hao-Chung Cheng , Frédéric Dupuis , Li Gao

The reliability of quantum channels for transmitting information is of profound importance from the perspective of quantum information. This naturally leads to the question as how well a quantum state is preserved when subjected to a…

Quantum Physics · Physics 2021-01-19 Javid Naikoo , Subhashish Banerjee , R. Srikanth

I derive a tight bound between the quality of estimating the state of a single copy of a $d$-level system, and the degree the initial state has to be altered in course of this procedure. This result provides a complete analytical…

Quantum Physics · Physics 2009-11-06 Konrad Banaszek

The minimal evolution time between two distinguishable states is of fundamental interest in quantum physics. Very recently Mirkin et al. argue that some most common quantum-speed-limit (QSL) bounds which depend on the actual evolution time…

Quantum Physics · Physics 2017-05-31 Xin Liu , Wei Wu , Chao Wang

We derive dynamics-independent upper bounds on achievable quantum state transformations. Modeling the evolution as a joint unitary on the system and its environment, we show that the R\'enyi divergence between the initial system state and…

Quantum Physics · Physics 2025-08-20 Yoshihiko Hasegawa

Local state transformation is the problem of transforming an arbitrary number of copies of a bipartite resource state to a bipartite target state under local operations. That is, given two bipartite states, is it possible to transform an…

Quantum Physics · Physics 2024-12-31 Payam Delgosha , Salman Beigi

Quantum-mechanical constraints on information transfer in measuring systems and their influence on measurement results studied. As the example, measurement of binary observable $S_z$ of object $\cal S$ by measuring apparatus $\cal A$…

Quantum Physics · Physics 2025-05-22 S. Mayburov

Fast quantum data transmission faces several shortcomings such as the indistinguishability of some partly overlapping signals, the channel noises, and so on. Based on the encoded quantum data transmission protocol, an unconventional scheme…

Quantum Physics · Physics 2017-08-31 Weidong Tang , Sixia Yu

We use a novel formation to illustrate the ($\alpha,\beta,\gamma$) modified weighted Wigner-Yanase-Dyson (($\alpha,\beta,\gamma$) MWWYD) skew information of quantum channels. By using operator norm inequalities, we explore the sum…

Quantum Physics · Physics 2023-10-24 Cong Xu , Zhaoqi Wu , Shao-Ming Fei

According to the Heisenberg uncertainty principle between time and energy fluctuation, a concept of the quantum speed limit (QSL) has been established to determine the minimum evolutionary time between quantum states. Considerable…

Quantum Physics · Physics 2023-08-08 Fu-Quan Dou , Min-Peng Han , Chuan-Cun Shu

Quantitative analysis of discontinuity of basic characteristics of quantum states and channels is presented. First we consider general estimates for discontinuity jump (loss) of the von Neumann entropy for a given converging sequence of…

Quantum Physics · Physics 2021-09-28 M. E. Shirokov

Convex functions of quantum states play a key role in quantum physics, with examples ranging from Bell inequalities to von Neumann entropy. However, in experimental scenarios, direct measurements of these functions are often impractical. We…

Quantum Physics · Physics 2024-08-21 Leonardo Zambrano , Donato Farina , Egle Pagliaro , Marcio M. Taddei , Antonio Acin

The Holevo quantity provides an upper bound for the mutual information between the sender of a classical message encoded in quantum carriers and the receiver. Applying the strong sub-additivity of entropy we prove that the Holevo quantity…

Quantum Physics · Physics 2015-05-18 Wojciech Roga , Mark Fannes , Karol Zyczkowski

In a quantum measurement process, classical information about the measured system spreads throughout the environment. Meanwhile, quantum information about the system becomes inaccessible to local observers. Here we prove a result about…

Quantum Physics · Physics 2021-09-29 Xiao-Liang Qi , Daniel Ranard