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Related papers: Parametrization of Quantum States and Channels

200 papers

In the current noisy intermediate-scale quantum (NISQ) era, quantum machine learning is emerging as a dominant paradigm to program gate-based quantum computers. In quantum machine learning, the gates of a quantum circuit are parametrized,…

Quantum Physics · Physics 2022-06-15 Osvaldo Simeone

For many-particle systems, quantum information in base n can be defined by partitioning the set of states according to the outcomes of n-ary (joint) observables. Thereby, k particles can carry k nits. With regards to the randomness of…

Quantum Physics · Physics 2015-06-26 Karl Svozil

Non-unitary protocols are already at the base of many hybrid quantum computing applications, especially in the noisy intermediate-scale quantum (NISQ) era where quantum errors typically affect the unitary evolution. However, while the…

Quantum Physics · Physics 2025-02-05 Giuseppe Clemente , Kevin Zambello

We introduce a new "positive formalism" for encoding quantum theories in the general boundary formulation, somewhat analogous to the mixed state formalism of the standard formulation. This makes the probability interpretation more natural…

Quantum Physics · Physics 2013-10-14 Robert Oeckl

In this thesis I present a short review of ideas in quantum information theory. The first chapter contains introductory material, sketching the central ideas of probability and information theory. Quantum mechanics is presented at the level…

Quantum Physics · Physics 2007-05-23 Robert H. Schumann

This work shows an approach to reduce the dimensionality of matrix representations of quantum channels. It is achieved by finding a base of the cone of positive semidefinite matrices which represent quantum channels. Next, this is…

Quantum Physics · Physics 2023-04-12 Paulina Lewandowska , Ryszard Kukulski , Łukasz Pawela

Quantum applications transmit and receive data through quantum and classical communication channels. Channel capacity, the distance and the photon path between transmitting and receiving parties and the speed of the computation links play…

Quantum Physics · Physics 2018-05-16 Mee Seong Im , Venkat R. Dasari

Particle statistics is a fundamental part of quantum physics, and yet its role and use in the context of quantum information have been poorly explored so far. After briefly introducing particle statistics and the Symmetrization Postulate, I…

Quantum Physics · Physics 2007-05-23 Y. Omar

Concomitant with the rapid development of quantum technologies, challenging demands arise concerning the certification and characterization of devices. The promises of the field can only be achieved if stringent levels of precision of…

Quantum Physics · Physics 2020-07-03 J. Eisert , D. Hangleiter , N. Walk , I. Roth , D. Markham , R. Parekh , U. Chabaud , E. Kashefi

Using Grothendieck approach to the tensor product of locally convex spaces we review a characterization of positive maps as well as Belavkin-Ohya characterization of PPT states. Moreover, within this scheme, \textit{ a generalization of the…

Quantum Physics · Physics 2015-06-19 Wladyslaw A. Majewski

I discuss the role that relativistic considerations play in quantum information processing. First I describe how the causality requirements limit possible multi-partite measurements. Then the Lorentz transformations of quantum states are…

Quantum Physics · Physics 2007-05-23 Daniel R. Terno

Tomograms introduced for the description of quantum states in terms of probability distributions are shown to be related to a standard star-product quantization with appropriate kernels. Examples of symplectic tomograms and spin tomograms…

Quantum Physics · Physics 2017-08-23 Olga V. Man'ko , Vladimir I. Man'ko , Giuseppe Marmo

The present Thesis covers the subject of the characterization of entangled states by recourse to entropic measures, as well as the description of entanglement related to several issues in quantum mechanics, such as the speed of a quantum…

Quantum Physics · Physics 2009-09-29 Josep Batle-Vallespir

The multi-access channels in quantum information theory are considered. Classical messages from independent sources, which are represented as some quantum states, are transported by a channel to one address. The messages can interact with…

Quantum Physics · Physics 2007-05-23 A. E. Allahverdyan , D. B. Saakian

This article reviews the extraordinary features of quantum information predicted by the quantum formalism, which, combined with the development of modern quantum technologies, have opened new horizons in quantum physics that can potentially…

Quantum Physics · Physics 2021-04-29 Ryszard Horodecki

One of the most challenging open problems in quantum information theory is to clarify and quantify how entanglement behaves when part of an entangled state is sent through a quantum channel. Of central importance in the description of a…

Quantum Physics · Physics 2007-05-23 Frank Verstraete , Henri Verschelde

A method is given by which the descriptive content of quantum state information can be encoded into subparticle coordinates. This method is consistent with the MA-model solution to the general grand unification problem. Subparticle…

Quantum Physics · Physics 2010-11-23 Robert A. Herrmann

State preparation is a necessary component of many quantum algorithms. In this work, we combine a method for efficiently representing smooth differentiable probability distributions using matrix product states with recently discovered…

Quantum Physics · Physics 2024-02-19 Jason Iaconis , Sonika Johri , Elton Yechao Zhu

A parametrization of density operators for bipartite quantum systems is proposed. It is based on the particular parametrization of the unitary group found recently by Jarlskog. It is expected that this parametrization will find interesting…

Quantum Physics · Physics 2009-10-20 Erwin Bruening , Dariusz Chruscinski , Francesco Petruccione

In this paper we propose a general method to quantify how "quantum" a set of quantum states is. The idea is to gauge the quantumness of the set by the worst-case difficulty of transmitting the states through a purely classical communication…

Quantum Physics · Physics 2007-05-23 Christopher A. Fuchs , Masahide Sasaki