English
Related papers

Related papers: Fidelity preserving and decoherence for mixed unit…

200 papers

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

High-fidelity quantum entanglement is a key resource for quantum communication and distributed quantum computing, enabling quantum state teleportation, dense coding, and quantum encryption. Any sources of decoherence in the communication…

We propose the notion of faithful coherent states based on the fidelity-based coherence witness. The criterion for detecting faithful coherent states can be restricted to a subclass of fidelity-based criterion under unitary transformations…

Quantum Physics · Physics 2022-10-05 Jun Li , Lin Chen

We analyze the quality of the quantum information transmission along a correlated quantum channel by studying the average fidelity between input and output states and the average output purity, giving bounds for the entropy of the channel.…

Quantum Physics · Physics 2008-11-26 Davide Rossini , Vittorio Giovannetti , Simone Montangero

We identify and characterize all the local quantum channels that preserves the set of classical states, i.e., does not create any quantum correlations. At first we show that the quantum correlations cannot be created from without if and…

Quantum Physics · Physics 2011-12-30 Sixia Yu , Chengjie Zhang , Qing Chen , C. H. Oh

Dissipationless localized bound states of open quantum systems are significantly robust to decoherence and have potential applications in quantum technologies. In this work, the decoherence dynamics and dissipationless localized bound…

Quantum Physics · Physics 2024-10-29 Chia-Yi Lin , Chuan-Zhe Yao , Hon-Lam Lai , Chin-Chun Tsai , Wei-Min Zhang

Spontaneous symmetry breaking mechanism in quantum phase transitions manifests the existence of degenerate groundstates in broken symmetry phases. To detect such degenerate groundstates, we introduce a quantum fidelity as an overlap…

Statistical Mechanics · Physics 2013-09-11 Yao Heng Su , Bing-Quan Hu , Sheng-Hao Li , Sam Young Cho

We present an "uncertainty principle" for quantum channels, showing a relationship between the dimensions of the range of a channel and the range of its complement. We examine some interesting specific cases, and discuss consequences for…

Quantum Physics · Physics 2016-11-22 Jeremy Levick

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

We derive exact analytical expressions for the quantum capacity of a broad subclasses of generalized dephasing channels of the form $\Lambda(\rho)=(1-x)\rho + x D(\rho)$, where $D(\rho)$ represents a structured decoherence process. These…

Quantum Physics · Physics 2025-11-26 Shayan Roofeh , Vahid Karimipour

Quantum correlation can be created by a local operation from some initially classical states. We prove that the necessary and sufficient condition for a local trace-preserving channel to create quantum correlation is that it is not a…

Quantum Physics · Physics 2012-03-08 Xueyuan Hu , Heng Fan , D. L. Zhou , Wu-Ming Liu

We investigate an imbalance between the sensitivity of the common state measures--fidelity, trace distance, concurrence, tangle, von Neumann entropy and linear entropy--when acted on by a depolarizing channel. Further, in this context we…

Quantum Physics · Physics 2007-05-23 Nicholas A. Peters , Tzu-Chieh Wei , Paul G. Kwiat

The uncertainty relation is a distinctive characteristic of quantum theory. The uncertainty is essentially rooted in quantum states. In this work we regard the uncertainty as an intrinsic property of quantum state and characterize it…

Quantum Physics · Physics 2024-05-31 Ming-Jing Zhao , Yuanhong Tao

The construction of large, coherent quantum systems necessary for quantum computation remains an entreating but elusive goal, due to the ubiquitous nature of decoherence. Recent progress in quantum error correction schemes have given new…

Quantum Physics · Physics 2008-02-03 Isaac L. Chuang , Yoshihisa Yamamoto

Quantum coherence, quantum entanglement and quantum nonlocality are important resources in quantum information precessing. However, decoherence happens when a quantum system interacts with the external environments. We study the dynamical…

Quantum Physics · Physics 2023-09-06 Tinggui Zhang , Hong Yang , Shao-Ming Fei

Effective information transmission is a central element in quantum information protocols, but the quest for optimal efficiency in channels with symmetrical characteristics remains a prominent challenge in quantum information science. In…

Quantum Physics · Physics 2023-11-02 Atta ur Rahman , S. M. Zangi , Ma-Cheng Yang , Cong-Feng Qiao

Assessing the quality of an ensemble of noisy entangled states is a central task in quantum information processing. Usually this is done by measuring and hence destroying multiple copies, from which state tomography or fidelity estimation…

Quantum Physics · Physics 2023-02-14 Ferran Riera-Sàbat , Jorge Miguel-Ramiro , Wolfgang Dür

One of the fundamental arguments in quantum information theory is the uncertainty principle. In accordance with this principle, two incompatible observables cannot be measured with high precision at the same time. In this work, we will use…

Quantum Physics · Physics 2024-01-26 Shahram Mehrmanesh , Maryam Hadipour , Soroush Haseli

Originated from the superposition principle in quantum mechanics, coherence has been extensively studied as a kind important resource in quantum information processing. We investigate the distinguishability of coherence-breaking channels…

Quantum Physics · Physics 2019-09-04 Long-Mei Yang , Tao Li , Shao-Ming Fei , Zhi-Xi Wang

We consider fundamental problems on the understanding of the tunneling phenomena in the context of the multi-dimensional wave function. In this paper, we reconsider the quantum state after tunneling and extend our previous formalism to the…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Takahiro Tanaka