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Related papers: Quantum Coding Theorem for Mixed States

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We derive upper bounds for Hilbert-Schmidt's quantum coherence of general states of a $d$-level quantum system, a qudit, in terms of its incoherent uncertainty, with the latter quantified using the linear and von Neumann's entropies of the…

Quantum Physics · Physics 2020-07-22 Marcos L. W. Basso , Diego S. S. Chrysosthemos , Jonas Maziero

Recent advances have defined nontrivial phases of matter in open quantum systems, such as many-body quantum states subject to environmental noise. In this work, we experimentally probe and characterize mixed-state phases on Quantinuum's H1…

Quantum Physics · Physics 2025-05-07 Yuxuan Zhang , Timothy H. Hsieh , Yong Baek Kim , Yijian Zou

We define the model of quantum circuits with density matrices, where non-unitary gates are allowed. Measurements in the middle of the computation, noise and decoherence are implemented in a natural way in this model, which is shown to be…

Quantum Physics · Physics 2007-05-23 Dorit Aharonov , Alexei Kitaev , Noam Nisan

We define a quantum entropy conditioned on post-selection which has the von Neumann entropy of pure states as a special case. This conditional entropy can take negative values which is consistent with part of a quantum system containing…

Quantum Physics · Physics 2014-09-05 Sina Salek , Roman Schubert , Karoline Wiesner

The states of the qubit, the basic unit of quantum information, are $2 \times 2$ positive semi-definite Hermitian matrices with trace 1. We contribute to the program to axiomatize quantum mechanics by characterizing these states in terms of…

Quantum Physics · Physics 2024-01-18 Adam Brandenburger , Pierfrancesco La Mura , Stuart Zoble

In the study of quantum limits to parameter estimation, the high dimensionality of the density operator and that of the unknown parameters have long been two of the most difficult challenges. Here we propose a theory of quantum…

Quantum Physics · Physics 2020-08-05 Mankei Tsang , Francesco Albarelli , Animesh Datta

In previous work, we have proposed an entanglement indicator for a general multiqubit state, which can be "learned" by a quantum system, acting as a neural network. The indicator can be used for a pure or a mixed state, and it need not be…

Quantum Physics · Physics 2017-02-07 E. C. Behrman , N. H. Nguyen , J. E. Steck , M. McCann

In order to compress quantum messages without loss of information it is necessary to allow the length of the encoded messages to vary. We develop a general framework for variable-length quantum messages in close analogy to the classical…

Quantum Physics · Physics 2009-11-07 Kim Bostroem , Timo Felbinger

In this paper, we study the bipartite entanglement of spin coherent states in the case of pure and mixed states. By a proper choice of the subsystem spins, the entanglement for large class of quantum systems is investigated. We generalize…

Quantum Physics · Physics 2015-06-12 K. Berrada , A. Mohammadzade , S. Abdel-Khalek , H. Eleuch , S. Salimi

The general scheme of data compression using the quantum noiseless coding theorem of Schumacher is dicussed for general quantum sources. When the Hilbert space of the quantum source is decomposable into orthogonal subspaces, one can first…

Quantum Physics · Physics 2007-05-23 K. Y. Szeto

This paper introduces a new inequality in algorithmic information theory that can be seen as an extended coding theorem. This inequality has applications in new bounds between quantum complexity measures.

Computational Complexity · Computer Science 2021-01-25 Samuel Epstein

We establish a generalisation of the fundamental state convertibility theorem in quantum information to the context of bipartite quantum systems modelled by commuting semi-finite von Neumann algebras. Namely, we establish a generalisation…

Operator Algebras · Mathematics 2020-09-15 Jason Crann , David W. Kribs , Rupert H. Levene , Ivan G. Todorov

Let S be the von Neumann entropy of a finite ensemble E of pure quantum states. We show that S may be naturally viewed as a function of a set of geometrical volumes in Hilbert space defined by the states and that S is monotonically…

Quantum Physics · Physics 2009-11-10 Graeme Mitchison , Richard Jozsa

Information theory is introduced in this lecture note with a particular emphasis on its relevance to algebraic coding theory. The document develops the mathematical foundations for quantifying uncertainty and information transmission by…

Information Theory · Computer Science 2025-12-08 El Mahdi Mouloua , Essaid Mohamed

The coupon collector is a prototypical model for evaluating the number of samples for identifying a set. By superposing all elements in the set as a pure quantum state, a quantum version of the coupon collector aims to learn the state,…

Quantum Physics · Physics 2024-06-18 Jing-Peng Zhang , Min-Quan He , Dan-Bo Zhang

Environmental interactions are ubiquitous in any real-world application of a quantum information processing protocol. Such interactions result in depletion of quantum resources. Two important figure of merits in the context of quantum…

Quantum Physics · Physics 2024-06-06 Tapaswini Patro , Kaushiki Mukherjee , Nirman Ganguly

We propose a method to perform precision measurements of the interaction parameters in systems of N ultra-cold spin 1/2 atoms. The spectroscopy is realized by first creating a coherent spin superposition of the two relevant internal states…

Other Condensed Matter · Physics 2009-11-13 A. M. Rey , L. Jiang , M. D. Lukin

We propose a quantum soft-covering problem for a given general quantum channel and one of its output states, which consists in finding the minimum rank of an input state needed to approximate the given channel output. We then prove a…

Quantum Physics · Physics 2024-09-25 Touheed Anwar Atif , S. Sandeep Pradhan , Andreas Winter

We propose a new measure of quantum entanglement. Our measure is defined in terms of conditional information transmission for a Quantum Bayesian Net. We show that our measure is identically equal to the Entanglement of Formation in the case…

Quantum Physics · Physics 2007-05-23 Robert R. Tucci

We discuss dense coding with $n$ copies of a specific preshared state between the sender and the receiver when the encoding operation is limited to the application of group representation. Typically, to act on multiple local copies of these…

Quantum Physics · Physics 2024-06-25 Ryuji Takagi , Masahito Hayashi