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Related papers: Cloning Quantum Channels

200 papers

We introduce an approach to quantum cloning based on spin networks and we demonstrate that phase covariant cloning can be realized using no external control but only with a proper design of the Hamiltonian of the system. In the 1 -> 2…

Quantum Physics · Physics 2009-11-10 G. De Chiara , R. Fazio , C. Macchiavello , S. Montangero , G. M. Palma

This paper presents a series of results on the interplay between quantum estimation, cloning and finite de Finetti theorems. First, we consider the measure-and-prepare channel that uses optimal estimation to convert M copies into k…

Quantum Physics · Physics 2011-03-16 Giulio Chiribella

We derive a lower bound for the optimal fidelity for deterministic cloning a set of n pure states. In connection with states estimation, we obtain a lower bound about average maximum correct states estimation probability.

Quantum Physics · Physics 2009-10-31 Chuan-Wei Zhang , Chuan-Feng Li , Guang-Can Guo

We investigate the optimal distribution of quantum information over multipartite systems in asymmetric settings. We introduce cloning transformations that take $N$ identical replicas of a pure state in any dimension as input, and yield a…

Quantum Physics · Physics 2009-11-10 S. Iblisdir , A. Acin , N. Gisin , J. Fiurasek , R. Filip , N. J. Cerf

To decide whether a quantum channel is degradable is relatively easy: one has to find at least one example of a degrading quantum channel. But in general, no conclusive criterion exists to show the opposite. Using elementary methods we…

Quantum Physics · Physics 2015-12-18 Kamil Bradler

Probabilistic quantum cloning and identifying machines can be constructed via unitary-reduction processes [Duan and Guo, Phys. Rev. Lett. 80, 4999 (1998)]. Given the cloning (identifying) probabilities, we derive an explicit representation…

Quantum Physics · Physics 2009-10-31 Chuan-Wei Zhang , Zi-Yang Wang , Chuan-Feng Li , Guang-Can Guo

Quantum state purification is crucial in quantum communication and computation, aiming to recover a purified state from multiple copies of an unknown noisy state. This work introduces a general state purification framework designed to…

Quantum Physics · Physics 2024-09-27 Hongshun Yao , Yu-Ao Chen , Erdong Huang , Kaichu Chen , Honghao Fu , Xin Wang

The inherent limitations of physical processes prevent the copying of arbitrary quantum states. Furthermore, even if we only aim to clone two distinct quantum states, it remains impossible unless they are mutually orthogonal. To overcome…

Quantum Physics · Physics 2025-07-24 Zhi-Hao Bi , Jing-Tao Qiu , Xiao-Dong Yu

Cloning machines, that is, transformations that achieve the best approximate copying of a quantum state compatible with the no-cloning theorem, have been a fundamental research topic over the last five years. This study is of particular…

Quantum Physics · Physics 2007-05-23 Nicolas J. Cerf

We study the process of quantum telecloning of $d$-dimensional pure quantum states using partially entangled pure states as quantum channel. This process efficiently mixes optimal universal symmetric cloning with quantum teleportation. It…

Quantum Physics · Physics 2017-12-05 Gabriel Araneda , Nataly Cisternas , Aldo Delgado

We discuss the usefulness of quantum cloning and present examples of quantum computation tasks for which cloning offers an advantage which cannot be matched by any approach that does not resort to it. In these quantum computations, we need…

Quantum Physics · Physics 2007-05-23 Gao Ting , Yan Feng-Li , Wang Zhi-Xi

Quantum coherence (QCh) is considered to be a key ingredient in quantum resource theories and also plays a pivotal role in the design and implementation of various information processing tasks. Consequently, it becomes important for us to…

Quantum Physics · Physics 2017-11-22 Indranil Chakrabarty , Udit Kamal Sharma , Manish Kumar Shukla

An application of quantum cloning to optimally interface a quantum system with a classical observer is presented, in particular we describe a procedure to perform a minimal disturbance measurement on a single qubit by adopting a 1->2…

Quantum Physics · Physics 2009-11-11 M. Ricci , F. Sciarrino , N. J. Cerf , R. Filip , J. Fiurasek , F. De Martini

Perfect cloning of a known set of states with arbitrary prior probabilities is possible if we allow the cloner to sometimes fail completely. In the optimal case the probability of failure is at its minimum allowed by the laws of quantum…

Quantum Physics · Physics 2016-09-08 E. Bagan , V. Yerokhin , A. Shehu , E. Feldman , J. A. Bergou

we envisage a novel quantum cloning machine, which takes an input state and produces an output state whose success branch can exist in a linear superposition of multiple copies of the input state and the failure branch exist in a…

Quantum Physics · Physics 2009-01-23 Arun Kumar Pati

A quantum channel is conjugate degradable if the channel's environment can be simulated up to complex conjugation using the channel's output. For all such channels, the quantum capacity can be evaluated using a single-letter formula. In…

Quantum Physics · Physics 2010-07-19 Kamil Bradler , Nicolas Dutil , Patrick Hayden , Abubakr Muhammad

We apply semidefinite programming for designing 1 to 2 symmetric qubit quantum cloners. These are optimized for the average fidelity of their joint output state with respect to a product of multiple originals. We design 1 to 2 quantum bit…

Quantum Physics · Physics 2013-07-19 Mátyás Koniorczyk , Lívia Dani , Vladimír Bužek

If a quantum system is subject to noise, it is possible to perform quantum error correction reversing the action of the noise if and only if no information about the system's quantum state leaks to the environment. In this article, we…

Quantum Physics · Physics 2012-07-06 Patrick Hayden , Andreas Winter

We present Quantum Cloning Machines (QCM) that transform N identical qubits into $M>N$ identical copies and we prove that the fidelity (quality) of these copies is optimal. The connection between cloning and measurement is discussed in…

Quantum Physics · Physics 2009-01-23 N. Gisin , S. Massar

The impossibility of simultaneously cloning non-orthogonal states lies at the foundations of quantum theory. Even when allowing for approximation errors, cloning an arbitrary unknown pure state requires as many initial copies as needed to…

Quantum Physics · Physics 2026-04-17 Nikhil Bansal , Matthias C. Caro , Gaurav Mahajan