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Related papers: Universal Asymmetric Quantum Cloning Revisited

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We study the mapping which occurs when a single qubit in an arbitrary state interacts with another qubit in a given, fixed state resulting in some unitary transformation on the two qubit system which, in effect, makes two copies of the…

Quantum Physics · Physics 2009-10-31 Chi-Sheng Niu , Robert B. Griffiths

Quantum control aims to manipulate quantum systems toward specific quantum states or desired operations. Designing highly accurate and effective control steps is vitally important to various quantum applications, including energy…

Quantum Physics · Physics 2023-01-11 Xinyu Fei , Lucas T. Brady , Jeffrey Larson , Sven Leyffer , Siqian Shen

We present the first experimental demonstration of the ''optimal'' and ''universal'' quantum entangling process involving qubits encoded in the polarization of single photons. The structure of the ''quantum entangling machine'' consists of…

Quantum Physics · Physics 2009-11-10 Fabio Sciarrino , Francesco De Martini , Vladimir Buzek

We compare several optical implementations of phase-covariant cloning machines. The experiments are based on copying of the polarization state of a single photon in bulk optics by special unbalanced beam splitter or by balanced beam…

Quantum Physics · Physics 2008-04-04 J. Soubusta , L. Bartuskova , A. Cernoch , J. Fiurasek , M. Dusek

Here we describe a Nuclear Magnetic Resonance (NMR) experiment that uses a three qubit NMR device to implement the one to two approximate quantum cloning network of Buzek et al.

Quantum Physics · Physics 2007-05-23 H. K. Cummins , C. Jones , A. Furze , N. F. Soffe , M. Mosca , J. M. Peach , J. A. Jones

We give a definition of asymmetric universal entangling machine which entangles a system in an unknown state to a specially prepared ancilla. The machine produces a fixed state-independent amount of entanglement in exchange to a fixed…

Quantum Physics · Physics 2014-09-24 Dmitri Horoshko , Mikhail Kolobov , Sergei Kilin

Due to the no-cloning theorem, the unknown quantum state can only be cloned approximately or exactly with some probability. There are two types of cloners: universal and state-dependent cloner. The optimal universal cloner has been found…

Quantum Physics · Physics 2009-11-07 Y. -J. Han , Y. -S. Zhang , G. -C. Guo

The problem of resolving the fine details of a signal from its coarse scale measurements or, as it is commonly referred to in the literature, the super-resolution problem arises naturally in engineering and physics in a variety of settings.…

Information Theory · Computer Science 2015-04-14 Tamir Bendory , Shai Dekel , Arie Feuer

We introduce an optimisation method for variational quantum algorithms and experimentally demonstrate a 100-fold improvement in efficiency compared to naive implementations. The effectiveness of our approach is shown by obtaining…

We propose a feasible scheme to implement the 1-to-2 optimal cloning transformation for two pairs of orthogonal states of two-dimensional quantum systems in the context of cavity QED. The copied qubits are shown to be inseparable by using…

Quantum Physics · Physics 2009-11-10 Zhuo-Liang Cao , Wei Song

The procedure commonly used in textbooks for determining the eigenvalues and eigenstates for a particle in an attractive Coulomb potential is not symmetric in the way the boundary conditions at $r=0$ and $r \rightarrow \infty$ are…

General Physics · Physics 2018-01-09 A. A. Othman , M. de Montigny , F. Marsiglio

Inevitably, assessing the overall performance of a quantum computer must rely on characterizing some of its elementary constituents and, from this information, formulate a broader statement concerning more complex constructions thereof.…

Quantum Physics · Physics 2019-08-14 Arnaud Carignan-Dugas , Matthew Alexander , Joseph Emerson

We present the first experimental implementation of a multifunctional device for the optimal cloning of one to two qubits. Previous implementations have always been designed to optimize the cloning procedure with respect to one single type…

Quantum Physics · Physics 2012-05-28 Karel Lemr , Karol Bartkiewicz , Antonin Cernoch , Jan Soubusta , Adam Miranowicz

Bosonic rotation codes, introduced here, are a broad class of bosonic error-correcting codes based on phase-space rotation symmetry. We present a universal quantum computing scheme applicable to a subset of this class--number-phase…

Quantum Physics · Physics 2020-03-11 Arne L. Grimsmo , Joshua Combes , Ben Q. Baragiola

The cloning of continuous quantum variables is analyzed based on the concept of Gaussian cloning machines, i.e., transformations that yield copies that are Gaussian mixtures centered on the state to be copied. The optimality of Gaussian…

Quantum Physics · Physics 2009-11-06 N. J. Cerf , S. Iblisdir

In this paper, we review some features of quantum annealing and related topics from viewpoints of statistical physics, condensed matter physics, and computational physics. We can obtain a better solution of optimization problems in many…

Disordered Systems and Neural Networks · Physics 2017-08-23 Shu Tanaka , Ryo Tamura

Binary classification is a fundamental problem in machine learning. Recent development of quantum similarity-based binary classifiers and kernel method that exploit quantum interference and feature quantum Hilbert space opened up tremendous…

Quantum Physics · Physics 2020-04-08 Daniel K. Park , Carsten Blank , Francesco Petruccione

Quantum annealing is a heuristic optimization algorithm that exploits quantum evolution to approximately find lowest energy states. Quantum annealers have scaled up in recent years to tackle increasingly larger and more highly connected…

Quantum Physics · Physics 2025-07-04 Humberto Munoz Bauza , Daniel A. Lidar

In the quantum regime information can be copied with only a finite fidelity. This fidelity gradually increases to 1 as the system becomes classical. In this article we show how this fact can be used to directly measure the amount of…

Quantum Physics · Physics 2015-05-19 Bruno Sanguinetti , Enrico Pomarico , Pavel Sekatski , Hugo Zbinden , Nicolas Gisin

A symmetric 1 to 2 quantum cloning machine (QCM) is presented that provides high-fidelity copies with $0.90 \le F \le 0.95$ for all pure (single-qubit) input states from a given meridian of the Bloch sphere. \cor{Emphasize is placed…

Quantum Physics · Physics 2010-03-30 Michael Siomau , Stephan Fritzsche