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It is shown that any quantum operation that perfectly clones the entanglement of all maximally-entangled qubit pairs cannot preserve separability. This ``entanglement no-cloning'' principle naturally suggests that some approximate cloning…

Quantum Physics · Physics 2009-11-10 Louis-Philippe Lamoureux , Patrick Navez , Jaromir Fiurasek , Nicolas J. Cerf

Transferring the state of an information carrier from a sender to a receiver is an essential primitive in both classical and quantum communication and information processing. In a quantum process known as teleportation the unknown state of…

In classical information theory, channel capacity quantifies the maximum number of messages that can be reliably transmitted using shared information. An equivalent concept, termed uncommon information, represents the number of messages…

Quantum Physics · Physics 2025-02-04 Yonghae Lee , Joonwoo Bae , Hayata Yamasaki , Soojoon Lee

Quantum masking is a special type of secret sharing in which some information gets reversibly distributed into a multipartite system, leaving the original information inaccessible to each subsystem. This paper proposes a dynamical extension…

Quantum Physics · Physics 2026-05-07 Anna Honeycutt , Hailey Murray , Eric Chitambar

Certain pure-state symmetry-protected topological orders (SPT) can be used as a resource for transmitting quantum information. Here, we investigate the ability to transmit quantum information using decohered SPT states, and relate this…

Quantum Physics · Physics 2024-05-10 Zhehao Zhang , Utkarsh Agrawal , Sagar Vijay

In quantum-state tomography on sources with quantum degrees of freedom of large Hilbert spaces, inference of quantum states of light for instance, a complete characterization of the quantum states for these sources is often not feasible…

Quantum Physics · Physics 2013-11-14 Yong Siah Teo , Jaroslav Rehacek , Zdenek Hradil

In this work, we consider optimal state discrimination for a quantum system that interacts with an environment, i.e., states evolve under a quantum channel. We show the conditions on a quantum channel and an ensemble of states such that a…

Quantum Physics · Physics 2019-06-12 Spiros Kechrimparis , Tanmay Singal , Chahan M. Kropf , Joonwoo Bae

The impossibility of undoing a mixing process is analysed in the context of quantum information theory. The optimal machine to undo the mixing process is studied in the case of pure states, focusing on qubit systems. Exploiting the symmetry…

Quantum Physics · Physics 2019-07-15 Farzad Kianvash , Marco Fanizza , Vittorio Giovannetti

Operational contextuality forms a rapidly developing subfield of quantum information theory. However, the characterization of the quantum mechanical entities that fuel the phenomenon has remained unknown with many partial results existing.…

The quantum prepare-and-measure scenario has been studied under various physical assumptions on the emitted states. Here, we first discuss how different assumptions are conceptually and formally related. We then identify one that can serve…

Quantum Physics · Physics 2025-02-19 Jef Pauwels , Stefano Pironio , Armin Tavakoli

The transfer of data is a fundamental task in information systems. Microprocessors contain dedicated data buses that transmit bits across different locations and implement sophisticated routing protocols. Transferring quantum information…

We present a network consisting of quantum gates which produces two imperfect copies of an arbitrary qubit. The quality of the copies does not depend on the input qubit. We also show that for a restricted class of inputs it is possible to…

Quantum Physics · Physics 2009-10-30 V. Buzek , S. L. Braunstein , M. Hillery , D. Bruss

The preparation of quantum states lies at the foundation in the quantum information processing. The convex mixing of some existing quantum states is one of the effective candidate. In this paper, we mainly study how a target quantum state…

Quantum Physics · Physics 2022-03-16 Li-qiang Zhang , Deng-hui Yu , Chang-shui Yu

Communication over a quantum multiple-access channel (MAC) with cribbing encoders is considered, whereby Transmitter 2 performs a measurement on a system that is entangled with Transmitter 1. Based on the no-cloning theorem, perfect…

Quantum Physics · Physics 2025-10-14 Uzi Pereg , Christian Deppe , Holger Boche

We, in this paper, analyze the efficacy of an output as a resource from a universal quantum cloning machine in information processing tasks such as teleportation and dense coding. For this, we have considered the $3\otimes 3$ dimensional…

Quantum Physics · Physics 2016-04-21 Sovik Roy , Nirman Ganguly , Atul Kumar , Satyabrata Adhikari , A. S. Majumdar

The linear superposition principle in quantum mechanics is essential for several no-go theorems such as the no-cloning theorem, the no-deleting theorem and the no-superposing theorem. It remains an open problem of finding general forbidden…

Quantum Physics · Physics 2018-06-26 Ming-Xing Luo , Hui-Ran Li , Hong Lai , Xiaojun Wang

A quantum cloning machine is introduced that yields $M$ identical optimal clones from $N$ replicas of a coherent state and $N'$ replicas of its phase conjugate. It also optimally produces $M'=M+N'-N$ phase-conjugated clones at no cost. For…

Quantum Physics · Physics 2009-11-07 N. J. Cerf , S. Iblisdir

The efficacies of maximally and that of non-maximally entangled mixed states as teleportation channels have been studied. A new class of non-maximally entangled mixed states have been proposed also. Their advantages as quantum teleportation…

Quantum Physics · Physics 2020-07-22 Sovik Roy

Incompatibility is a feature of quantum theory that sets it apart from classical theory, and the inability to clone an unknown quantum state is one of the most fundamental instances. The no-hiding theorem is another such instance that…

Quantum Physics · Physics 2025-08-12 Matthew Girling , Cristina Cirstoiu , David Jennings

In quantum systems, entanglement corresponds to nonclassical correlation of nonlocal observables. Thus, entanglement (or, to the contrary, separability) of a given quantum state is not uniquely determined by properties of the state, but may…

Quantum Physics · Physics 2012-05-21 Iacopo Pozzana
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