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The evolution of a quantum system interacting with an environment can be described as a unitary process acting on both the system and the environment. In this framework, the system's evolution can be predicted by tracing out the…

We model the transport of an unknown quantum state on one dimensional qubit lattices by means of a quantum cellular automata evolution. We do this by first introducing a class of discrete noisy dynamics, in the first excitation sector, in…

Quantum Physics · Physics 2015-06-23 Michele Avalle , Marco G. Genoni , Alessio Serafini

The analysis conducted in this work indicates that interactions of a CP-violating (and CPT-preserving) quantum system with a thermodynamic environment can produce the impression of a CPT violation in the system. This conclusion is…

Quantum Physics · Physics 2015-06-18 A. Y. Klimenko

The central issue in this article is to transmit a quantum state in such a way that after some decoherence occurs, most of the information can be restored by a suitable decoding operation. For this purpose, we incorporate redundancy by…

Quantum Physics · Physics 2007-05-23 Bernhard G. Bodmann , David W. Kribs , Vern I. Paulsen

In this paper we study quantum communication channels with correlated noise effects, i.e., quantum channels with memory. We derive a model for correlated noise channels that includes a channel memory state. We examine the case where the…

Quantum Physics · Physics 2009-11-10 Garry Bowen , Stefano Mancini

We have proposed a scheme of the generation and preservation of two-qubit steady state quantum correlations through quantum channels where successive uses of the channels are correlated. Different types of noisy channels with memory, such…

Quantum Physics · Physics 2016-04-15 You-neng Guo , Mao-fa Fang , Guo-you Wang , Ke Zeng

The task of determining whether a given quantum channel has positive capacity to transmit quantum information is a fundamental open problem in quantum information theory. In general, the coherent information needs to be computed for an…

Quantum Physics · Physics 2022-08-17 Satvik Singh , Nilanjana Datta

If a quantum system is subject to noise, it is possible to perform quantum error correction reversing the action of the noise if and only if no information about the system's quantum state leaks to the environment. In this article, we…

Quantum Physics · Physics 2012-07-06 Patrick Hayden , Andreas Winter

We explore complementarity between output and environment of a quantum channel (or, more generally, CP map), making an observation that the output purity characteristics for complementary CP maps coincide. Hence, validity of the…

Quantum Physics · Physics 2007-07-05 A. S. Holevo

Coherent information quantifies the transmittable quantum information through a channel and is directly linked to the channel's quantum capacity. In a monitored quantum circuit, regarded as a quantum channel, extensive and positive coherent…

Quantum Physics · Physics 2025-12-11 Dongheng Qian , Jing Wang

The quantum capacity of degradable quantum channels has been proven to be additive. On the other hand, there is no general rule for the behavior of quantum capacity for non-degradable quantum channels. We introduce the set of partially…

Quantum Physics · Physics 2016-11-15 Laszlo Gyongyosi

Quantum channels, a subset of quantum maps, describe the unitary and non-unitary evolution of quantum systems. We study a generalization of the concept of Pauli maps to the case of multipartite high dimensional quantum systems through the…

Quantum Physics · Physics 2024-04-25 Tomas Basile , Jose Alfredo de Leon , Alejandro Fonseca , Francois Leyvraz , Carlos Pineda

We show that multipartite quantum states that have a positive partial transpose with respect to all bipartitions of the particles can outperform separable states in linear interferometers. We introduce a powerful iterative method to find…

Quantum Physics · Physics 2025-04-01 Géza Tóth , Tamás Vértesi

As quantum information systems mature, efficient and coherent transfer of quantum information through noisy channels becomes increasingly important. We examine how passive environment-assisted quantum communication enhances direct quantum…

Quantum Physics · Physics 2026-03-02 Evelyn Voss , Bikun Li , Zhaoyou Wang , Liang Jiang

Quantum dots are nanometer-scale semiconductor particles that exhibit size-dependent quantum mechanical properties. In this work, we investigate the dynamics of quantum correlations, quantified by the concurrence and the quantum coherence,…

We address the problem of finding optimal CPTP (completely positive, trace preserving) maps between a set of binary pure states and another set of binary generic mixed state in a two dimensional space. The necessary and sufficient…

Quantum Physics · Physics 2014-12-01 A. Carlini , M. Sasaki

We analyze the relation between CP-divisibility and the lack of information backflow for an arbitrary -- not necessarily invertible -- dynamical map. It is well known that CP-divisibility always implies lack of information backflow.…

Quantum Physics · Physics 2018-08-29 Dariusz Chruściński , Ángel Rivas , Erling Størmer

The present work analyzes state-stabilization techniques for decoupling a subsystem from environmental interactions. The proposed framework uses analytical and numerical tools to find an approximate decoherence-free subspace (DFS) with…

Quantum Physics · Physics 2025-07-11 Miguel Casanova , Francesco Ticozzi

Unital quantum channels, defined by their property of leaving the maximally mixed state invariant, form an important class of quantum operations. A distinguished subset of these channels can be represented as a probabilistic mixture of…

Quantum Physics · Physics 2026-03-19 Charlotte Bäcker , Konstantin Beyer , Walter T. Strunz

A general law is presented for (composite) quantum systems which directly describes the time evolution of quantum states (with one or both components) through an arbitrary noisy quantum channel. It is shown that the time evolution of all…

Quantum Physics · Physics 2009-06-21 Chang-shui Yu , He-shan Song