English
Related papers

Related papers: Tomographic portrait of quantum channels

200 papers

A characterization of qubit quantum channels is introduced. In analogy to what happens in the context of Bosonic channels we exploit the possibility of representing the states of the system in terms of characteristic function. The latter…

Quantum Physics · Physics 2007-10-25 Filippo Caruso , Vittorio Giovannetti

It is usually believed that a picture of Quantum Mechanics in terms of true probabilities cannot be given due to the uncertainty relations. Here we discuss a tomographic approach to quantum states that leads to a probability representation…

Quantum Physics · Physics 2007-05-23 Michele Caponigro , Stefano Mancini , Vladimir I. Man'ko

The set of quantum Gaussian channels acting on one bosonic mode can be classified according to the action of the group of Gaussian unitaries. We look for bounds on the classical capacity for channels belonging to such a classification.…

Quantum Physics · Physics 2011-03-03 Cosmo Lupo , Stefano Pirandola , Paolo Aniello , Stefano Mancini

Coherence is a basic notion for quantum states. Instead of quantum states, in this work, We establish a resource theory for quantifying the coherence of Gaussian channels. To do this, we propose the definitions of incoherent Gaussian…

Quantum Physics · Physics 2019-08-15 Jianwei Xu

We investigate the capacity of bosonic quantum channels for the transmission of quantum information. Achievable rates are determined from measurable moments of the channel by showing that every channel can asymptotically simulate a Gaussian…

Quantum Physics · Physics 2009-11-13 Michael M. Wolf , David Perez-Garcia , Geza Giedke

Gaussian quantum channels are well understood and have many applications, e.g., in Quantum Information Theory and in Quantum Optics. For more general quantum channels one can in general use semiclassical approximations or perturbation…

Quantum Physics · Physics 2023-05-16 Daniel Speed , Wenyang Lyu , Roman Schubert

A classification of one-mode Gaussian channels is given up to canonical unitary equivalence. A complementary to the quantum channel with additive classical Gaussian noise is described providing an example of one-mode Gaussian channel which…

Quantum Physics · Physics 2010-12-30 A. S. Holevo

Recently it was shown that the main distinguishing features of quantum mechanics (QM) can be reproduced by a model based on classical random fields, so called prequantum classical statistical field theory (PCSFT). This model provides a…

Quantum Physics · Physics 2012-10-17 Andrei Khrennikov , Masanori Ohya , Naboru Watanabe

We analyze qubit channels by exploiting the possibility of representing two-level quantum systems in terms of characteristic functions. To do so, we use functions of non-commuting variables (Grassmann variables), defined in terms of…

Quantum Physics · Physics 2008-09-12 Filippo Caruso , Vittorio Giovannetti

The coexistence of quantum and classical signals over the same optical fiber with minimal degradation of the transmitted quantum information is critical for operating large-scale quantum networks over the existing communications…

In this paper we are interested to model quantum signal by statistical signal processing methods. The Gaussian distribution has been considered for the input quantum signal as Gaussian state have been proven to a type of important robust…

Quantum Physics · Physics 2023-02-17 Mouli Chakraborty , Harun Siljak , Indrakshi Dey , Nicola Marchetti

We examine stochastic maps in the context of quantum optics. Making use of the master equation, the damping basis, and the Bloch picture we calculate a non-unital, completely positive, trace-preserving map with unequal damping eigenvalues.…

Quantum Physics · Physics 2009-11-07 Sonja Daffer , Krzysztof Wodkiewicz , John K. McIver

Continuous-variable quantum systems are foundational to quantum computation, communication, and sensing. While traditional representations using wave functions or density matrices are often impractical, the tomographic picture of quantum…

Quantum Physics · Physics 2026-03-17 Liubov A. Markovich , Xiaoyu Liu , Jordi Tura

Diagrammatic representation and manipulation of tensor networks has proven to be a useful tool in mathematics, physics, and computer science. Here we present several important and mostly well-known theorems regarding the dualities between…

Quantum Physics · Physics 2015-09-29 Ville Bergholm

This thesis explores ways in which quantum channels and correlations (of both classical and quantum types) manifest themselves, and also studies the interplay between these two aspects in various physical settings. Quantum channels…

Quantum Physics · Physics 2016-04-28 Krishna Kumar Sabapathy

Quantum Gaussian channels are fundamental models for communication and information processing in continuous-variable quantum systems. This work addresses both foundational aspects and physical implementation pathways for these channels.…

Quantum Physics · Physics 2025-05-08 Repana Devendra , Tiju Cherian John , K. Sumesh

I develop a theory of classicality from quantum systems. This theory stems from the study of classical and quantum stationary stochastic processes. The stochastic processes are characterized by polyhedral (classical) and semidefinite…

Quantum Physics · Physics 2023-11-27 Esteban Martínez-Vargas

We define a map which relates four dimensional classical stochastic matrices to qubit quantum channels. The map preserves the spectrum and the composition of processes. To do this we introduce the concept of Bloch tetrahedron which plays…

Quantum Physics · Physics 2011-08-30 Vahid Karimipour , Laleh Memarzadeh

Using the known possibility to associate the completely positive maps with density matrices and recent results on expressing the density matrices with sets of classical probability distributions of dichotomic random variables we construct…

Quantum Physics · Physics 2019-04-09 Ashot Avanesov , Vladimir I. Man'ko

Gaussian quantum channels have recently attracted a growing interest, since they may lead to a tractable approach to the generally hard problem of evaluating quantum channel capacities. However, the analysis performed so far has always been…

Quantum Physics · Physics 2010-02-18 Nicolas J. Cerf , Julien Clavareau , Jérémie Roland , Chiara Macchiavello
‹ Prev 1 2 3 10 Next ›