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Related papers: Quantum Channel Learning

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Many quantum information tasks use inputs of the form $\rho^{\otimes m}$, which naturally induce permutation and unitary symmetries. We classify all quantum channels that respect both symmetries - i.e. unitary-equivariant and…

Quantum Physics · Physics 2025-10-10 Laura Mančinska , Elias Theil

This document focuses on translating various information-theoretic measures of distinguishability for probability distributions into measures of distin- guishability for quantum states. These measures should have important appli- cations in…

Quantum Physics · Physics 2007-05-23 Christopher A. Fuchs

A quantum ensemble $\{(p_x, \rho_x)\}$ is a set of quantum states each occurring randomly with a given probability. Quantum ensembles are necessary to describe situations with incomplete a priori information, such as the output of a…

Quantum Physics · Physics 2009-03-30 Ognyan Oreshkov , John Calsamiglia

This paper concerns the study of optimal (supremum and infimum) uncertainty bounds for systems where the input (or prior) probability measure is only partially/imperfectly known (e.g., with only statistical moments and/or on a coarse…

Machine Learning · Computer Science 2023-01-02 Xingsheng Sun , Burigede Liu

Unambiguous unitary maps and unambiguous unitary quantum channels are introduced and some of their properties are derived. These properties ensure certain simple form for the measurements involved in realizing an unambiguous unitary quantum…

Quantum Physics · Physics 2008-11-14 Shengjun Wu , Xuemei Chen

While many problems in machine learning focus on learning mappings between finite-dimensional spaces, scientific applications require approximating mappings between function spaces, i.e., operators. We study the problem of learning…

Machine Learning · Computer Science 2025-10-30 Adrien Weihs , Jingmin Sun , Zecheng Zhang , Hayden Schaeffer

Quantum federated learning (QFL) combines the robust data processing of quantum computing with the privacy-preserving features of federated learning (FL). However, in large-scale wireless networks, optimizing sum-rate is crucial for…

Information Theory · Computer Science 2026-03-03 Shaba Shaon , Christopher G. Brinton , Dinh C. Nguyen

We discuss efficient methods to optimize the metrological performance over local Hamiltonians in a bipartite quantum system. For a given quantum state, our methods find the best local Hamiltonian for which the state outperforms separable…

Quantum Physics · Physics 2026-05-25 Árpád Lukács , Róbert Trényi , Tamás Vértesi , Géza Tóth

Hyperspectral unmixing (HU) plays a fundamental role in a wide range of hyperspectral applications. It is still challenging due to the common presence of outlier channels and the large solution space. To address the above two issues, we…

Computer Vision and Pattern Recognition · Computer Science 2017-08-29 Feiyun Zhu , Ying Wang , Bin Fan , Gaofeng Meng , Chunhong Pan

We associate to every quantum channel $T$ acting on a Hilbert space $\mathcal{H}$ a pair of Hamiltonian operators over the symmetric subspace of $\mathcal{H}^{\otimes 2}$. The expectation values of these Hamiltonians over symmetric product…

Quantum Physics · Physics 2007-05-23 Paolo Zanardi , Daniel Lidar

We study the problem of efficiently learning an unknown $n$-qubit unitary channel in diamond distance given query access. We present a general framework showing that if Pauli operators remain low-complexity under conjugation by a unitary,…

Quantum Physics · Physics 2026-04-07 Sabee Grewal , Daniel Liang

In recent years, there is a growing interest in using quantum computers for solving combinatorial optimization problems. In this work, we developed a generic, machine learning-based framework for mapping continuous-space inverse design…

Tradeoffs between the information rate and fidelity of quantum error-correcting codes are discussed. Quantum channels to be considered are those subject to independent errors and modeled as tensor products of copies of a general completely…

Quantum Physics · Physics 2016-11-18 Mitsuru Hamada

Maximum entropy inference and learning of graphical models are pivotal tasks in learning theory and optimization. This work extends algorithms for these problems, including generalized iterative scaling (GIS) and gradient descent (GD), to…

Machine Learning · Computer Science 2024-07-17 Minbo Gao , Zhengfeng Ji , Fuchao Wei

Variational quantum circuits for image classification suffer from barren plateaus, while quantum kernel methods scale quadratically with dataset size. We propose an iterative framework based on Quadratic Unconstrained Binary Optimization…

Quantum Physics · Physics 2026-03-04 Mostafa Atallah , Rebekah Herrman

We present strategies how to reconstruct (estimate) properties of a quantum channel described by the map E based on incomplete measurements. In a particular case of a qubit channel a complete reconstruction of the map E can be performed via…

Quantum Physics · Physics 2016-10-18 Mario Ziman , Martin Plesch , Vladimir Buzek

Random (mixed) unitary channels describe an important subset of quantum channels, which are commonly used in quantum information, noise modeling, and quantum error mitigation. Despite their usefulness, there is substantial complexity in…

Quantum Physics · Physics 2025-01-30 Scott E. Smart , Alexander Jürgens , Joseph Peetz , Prineha Narang

The study of quantum channels is the fundamental field and promises wide range of applications, because any physical process can be represented as a quantum channel transforming an initial state into a final state. Inspired by the method…

Quantum Physics · Physics 2017-06-27 Shi-Jie Wei , Tao Xin , Gui-Lu Long

Quantum state discrimination is a fundamental concept in quantum information theory, which refers to a class of techniques to identify a specific quantum state through a positive operator-valued measure. In this work, we investigate how…

Quantum Physics · Physics 2025-07-09 Hyunho Cha , Jungwoo Lee

To establish an entangled state of optimal fidelity between two distant observers when the available quantum channel is noisy, is a central problem in quantum information theory. We consider an instance of this problem for two-qubit systems…

Quantum Physics · Physics 2012-09-18 Somshubhro Bandyopadhyay , Anindita Ghosh