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Related papers: Quantum superreplication of states and gates

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The problem of quantum state reduction in the process of measurement has attracted attention of almost everyone who created, developed or explained quantum physics to the students. Absence of a solution is the basis for the statement that…

Quantum Physics · Physics 2017-09-11 Constantin V. Usenko

In this thesis, we investigate whether quantum algorithms can be used in the field of machine learning for both long and near term quantum computers. We will first recall the fundamentals of machine learning and quantum computing and then…

Quantum Physics · Physics 2021-11-08 Jonas Landman

Unmeasureability of a quantum state has important consequences in practical implementation of quantum computers. Like copying, deleting of an unknown state from among several copies is prohibited. This is called no-deletion prinicple. Here,…

Quantum Physics · Physics 2007-05-23 Arun K. Pati , Samuel L. Braunstein

The universality of a quantum neural network refers to its ability to approximate arbitrary functions and is a theoretical guarantee for its effectiveness. A non-universal neural network could fail in completing the machine learning task.…

Quantum Physics · Physics 2023-06-27 Xiaokai Hou , Guanyu Zhou , Qingyu Li , Shan Jin , Xiaoting 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

A major bottleneck in the quest for scalable many-body quantum technologies is the difficulty in benchmarking their preparations, which suffer from an exponential `curse of dimensionality' inherent to their quantum states. We present an…

Quantum Physics · Physics 2019-07-31 Juan Carrasquilla , Giacomo Torlai , Roger G. Melko , Leandro Aolita

Quantum algorithms profit from the interference of quantum states in an exponentially large Hilbert space and the fact that unitary transformations on that Hilbert space can be broken down to universal gates that act only on one or two…

Quantum Physics · Physics 2022-03-14 Daniel Braun , Ronny Müller

We build a general quantum state tomography framework that makes use of machine learning techniques to reconstruct quantum states from a given set of coincidence measurements. For a wide range of pure and mixed input states we demonstrate…

Quantum Physics · Physics 2020-06-09 Sanjaya Lohani , Brian T. Kirby , Michael Brodsky , Onur Danaci , Ryan T. Glasser

Any physical transformation that equally distributes quantum information over a large number M of users can be approximated by a classical broadcasting of measurement outcomes. The accuracy of the approximation is at least of the order 1/M.…

Quantum Physics · Physics 2007-05-23 G. Chiribella , G. M. D'Ariano

The method of quantum cloning is divided into two main categories: approximate and probabilistic quantum cloning. The former method is used to approximate an unknown quantum state deterministically, and the latter can be used to faithfully…

Quantum Physics · Physics 2015-05-27 Hongwei Chen , Dawei Lu , Bo Chong , Gan Qin , Xianyi Zhou , Xinhua Peng , Jiangfeng Du

There has been significant recent interest in quantum neural networks (QNNs), along with their applications in diverse domains. Current solutions for QNNs pose significant challenges concerning their scalability, ensuring that the…

Quantum Physics · Physics 2022-03-24 Mohsen Heidari , Ananth Grama , Wojciech Szpankowski

We present an example of quantum computational tasks whose performance is enhanced if we distribute quantum information using quantum cloning. Furthermore we give achievable efficiencies for probabilistic cloning the quantum states used in…

Quantum Physics · Physics 2009-11-10 Ting Gao , Fengli Yan , Zhixi Wang

This is the documentation for generating random samples from the quantum state space in accordance with a specified distribution, associated with this webpage: http://tinyurl.com/QSampling . Ready-made samples (each with at least a million…

When an informationally complete measurement is not available, the reconstruction of the density operator that describes the state of a quantum system can be accomplish, in a reliable way, by adopting the maximum entropy principle (MaxEnt…

Quantum Physics · Physics 2022-03-16 Diego Tielas , Marcelo Losada , Lorena Rebón , Federico Holik

Arbitrary quantum states cannot be copied. In fact, to make a copy we must provide complete information about the system. However, can a quantum system self-replicate? This is not answered by the no-cloning theorem. In the classical…

Quantum Physics · Physics 2007-05-23 Arun K. Pati , Samuel L. Braunstein

The identification of an unknown quantum gate is a significant issue in quantum technology. In this paper, we propose a quantum gate identification method within the framework of quantum process tomography. In this method, a series of pure…

Quantum Physics · Physics 2019-05-15 Yuanlong Wang , Qi Yin , Daoyi Dong , Bo Qi , Ian R. Petersen , Zhibo Hou , Hidehiro Yonezawa , Guo-Yong Xiang

Quantum metrology typically demands the preparation of exotic quantum probe states, such as entangled or squeezed states, to surpass classical limits. However, the need for carefully calibrated system parameters and finely optimized quantum…

The superposition principle is one of the landmarks of quantum mechanics. The importance of quantum superpositions provokes questions about the limitations that quantum mechanics itself imposes on the possibility of their generation. In…

Quantum Physics · Physics 2016-03-23 Michał Oszmaniec , Andrzej Grudka , Michał Horodecki , Antoni Wójcik

Estimation of quantum states and measurements is crucial for the implementation of quantum information protocols. The standard method for each is quantum tomography. However, quantum tomography suffers from systematic errors caused by…

Quantum Physics · Physics 2018-10-19 Adam C. Keith , Charles H. Baldwin , Scott Glancy , E. Knill

Measurement based (MB) quantum computation allows for universal quantum computing by measuring individual qubits prepared in entangled multipartite states, known as graph states. Unless corrected for, the randomness of the measurements…

Quantum Physics · Physics 2018-02-28 Rawad Mezher , Joe Ghalbouni , Joseph Dgheim , Damian Markham