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Related papers: Information capacity of quantum observable

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We study commitment scheme for classical-quantum channels. To accomplish this we define various notions of commitment capacity for these channels and prove matching upper and lower bound on it in terms of the conditional entropy. Our…

Information Theory · Computer Science 2022-05-06 Masahito Hayashi , Naqueeb Ahmad Warsi

Compound channel models offer a simple and straightforward way of analyzing the stability of decoder design under model variations. With this work we provide a coding theorem for a large class of practically relevant compound channel…

Information Theory · Computer Science 2021-05-11 Andrea Cacioppo , Janis Nötzel , Matteo Rosati

Since the beginning of quantum mechanics, many puzzling phenomena which distinguish the quantum from the classical world, have appeared such as complementarity, entanglement or contextuality. All of these phenomena are based on the…

Quantum Physics · Physics 2016-11-24 S. Wölk

We consider communication between two parties using a bipartite quantum operation, which constitutes the most general quantum mechanical model of two-party communication. We primarily focus on the simultaneous forward and backward…

Quantum Physics · Physics 2014-11-18 Andrew M. Childs , Debbie W. Leung , Hoi-Kwong Lo

The informational power of a quantum measurement is the maximum amount of classical information that the measurement can extract from any ensemble of quantum states. We discuss its main properties. Informational power is an additive…

Quantum Physics · Physics 2015-02-23 Michele Dall'Arno , Giacomo Mauro D'Ariano , Massimiliano F. Sacchi

We explore several new converse bounds for classical communication over quantum channels in both the one-shot and asymptotic regimes. First, we show that the Matthews-Wehner meta-converse bound for entanglement-assisted classical…

Quantum Physics · Physics 2019-08-07 Xin Wang , Kun Fang , Marco Tomamichel

The advent of cloud quantum computing has led to the rapid development of quantum algorithms. In particular, it is necessary to study variational quantum-classical hybrid algorithms, which are executable on noisy intermediate-scale quantum…

Quantum Physics · Physics 2020-07-02 Ikko Hamamura , Takashi Imamichi

One of the major achievements of the recently emerged quantum information theory is the introduction and thorough investigation of the notion of quantum channel which is a basic building block of any data-transmitting or data-processing…

Quantum Physics · Physics 2012-03-23 A. S. Holevo , V. Giovannetti

A quantum message is encoded into $N$ storage nodes (quantum systems $Q_1\dots Q_N$) with assistance from $N_B$ maximally entangled bi-partite quantum systems $A_1B_1, \dots, A_{N_B}B_{N_B}$, that are prepared in advance such that $B_1\dots…

Information Theory · Computer Science 2025-12-09 Hua Sun , Syed A. Jafar

We study the symmetric-side-channel-assisted private capacity of a quantum channel, for which we provide a single-letter formula. This capacity is additive, convex, and, for degradable channels, equal to the unassisted private capacity.…

Quantum Physics · Physics 2008-08-07 Graeme Smith

We consider controllability of two conjugate observables Z and X by two parties with classical communication. The ability is specified by two alternative tasks, (i) agreement on Z and (ii) preparation of an eigenstate of X with use of an…

Quantum Physics · Physics 2007-05-23 Masato Koashi

We provide a model to study memory effects in quantum Gaussian channels with additive classical noise over an arbitrary number of uses. The correlation among different uses is introduced by contiguous two-mode interactions. Numerical…

Quantum Physics · Physics 2007-05-23 Giovanna Ruggeri , Stefano Mancini

We investigate the problem of enhancement of mutual information by encoding classical data into entangled input states of arbitrary length and show that while there is a threshold memory or correlation parameter beyond which entangled…

Quantum Physics · Physics 2009-11-13 V. Karimipour , L. Memarzadeh

The capacity of noisy quantum channels characterizes the highest rate at which information can be reliably transmitted and it is therefore of practical as well as fundamental importance. Capacities of classical channels are computed using…

Quantum Physics · Physics 2021-07-02 Navneeth Ramakrishnan , Raban Iten , Volkher B. Scholz , Mario Berta

Entanglement, a defining property of quantum mechanics in which two physical subsystems cannot be seen as independent entities, challenges our everyday experience and classical intuition. However, only such strong quantum correlations…

Quantum Physics · Physics 2025-11-13 Enno Giese

The fundamental question of how information spreads in closed quantum many-body systems is often addressed through the lens of the bipartite entanglement entropy, a quantity that describes correlations in a comprehensive (nonlocal) way.…

Statistical Mechanics · Physics 2023-06-06 Andrea Pizzi , Daniel Malz , Andreas Nunnenkamp , Johannes Knolle

The rates at which classical and quantum information can be simultaneously transmitted from two spatially separated senders to a single receiver over an arbitrary quantum channel are characterized. Two main results are proved in detail. The…

Quantum Physics · Physics 2007-05-23 Jon Yard

We interpret the traversable wormhole in AdS/CFT in the context of quantum information theory. In particular, we investigate its properties as both a quantum channel and entanglement witness. We define protocols that allow either the…

High Energy Physics - Theory · Physics 2018-11-14 Ning Bao , Aidan Chatwin-Davies , Jason Pollack , Grant N. Remmen

The amount of information transmissible through a communications channel is determined by the noise characteristics of the channel and by the quantities of available transmission resources. In classical information theory, the amount of…

Quantum Physics · Physics 2009-11-10 Mikio Fujiwara , Masahiro Takeoka , Jun Mizuno , Masahide Sasaki

We study mixed unitary quantum channels generated by irreducible projective unitary representations of finite groups. Under some assumptions on the probability distribution determining a mixture the classical capacity of the channel is…

Quantum Physics · Physics 2022-05-26 Grigori Amosov