English
Related papers

Related papers: Quantum coherence of two-qubit over quantum channe…

200 papers

The coherence power of a quantum channel, that is, its ability to increase the coherence of input states, is a fundamental concept within the framework of the resource theory of coherence. In this note we discuss various possible…

Quantum Physics · Physics 2016-12-23 M. García-Díaz , D. Egloff , M. B. Plenio

Realizing a long coherence time quantum memory is a major challenge of current quantum technology. Here, we report a single \Yb ion-qubit memory with over one hour coherence time, an order of improvement compared to the state-of-the-art…

Quantum Physics · Physics 2021-02-02 Pengfei Wang , Chun-Yang Luan , Mu Qiao , Mark Um , Junhua Zhang , Ye Wang , Xiao Yuan , Mile Gu , Jingning Zhang , Kihwan Kim

For the case of phase damping (pure decoherence) we investigate the extent to which environmental traits are imprinted on an open quantum system. The dynamics is described using the quantum channel approach. We study what the knowledge of…

Quantum Physics · Physics 2015-05-20 Julius Helm , Walter T. Strunz , Stephan Rietzler , Lars Erik Würflinger

We investigate how the efficiency of the quantum teleportation protocol is affected when the qubits involved in the protocol are subjected to noise or decoherence. We study all types of noise usually encountered in real world…

Quantum Physics · Physics 2015-08-05 Raphael Fortes , Gustavo Rigolin

Criteria of measure quantifying quantum coherence, a unique property of quantum system, are proposed recently. In this paper, we first give an uncertainty-like expression relating the coherence and the entropy of quantum system. This…

Quantum Physics · Physics 2015-07-15 Zhengjun Xi , Yongming Li , Heng Fan

We investigate the coherence of quantum channels and establish a resource theory for quantifying the coherence of quantum channels via Choi matrix. To this aim, we define the incoherent channels and incoherent superchannels. This theory…

Quantum Physics · Physics 2019-11-12 Jianwei Xu

Quantum computers have now appeared in our society and are utilized for the investigation of science and engineering. At present, they have been built as intermediate-size computers containing about fifty qubits and are weak against noise…

Quantum Physics · Physics 2020-12-07 Yusuke Hama

Based on the quantum technique of weak measurement, we propose a scheme to protect the entanglement from correlated amplitude damping decoherence. In contrast to the results of memoryless amplitude damping channel, we show that the memory…

Quantum Physics · Physics 2022-09-14 Xing Xiao , Yao Yao , Ying-Mao Xie , Xing-Hua Wang , Yan-Ling Li

Quantum coherence and quantum correlations are of fundamental and practical significance for the development of quantum mechanics.They are also cornerstones of quantum computation and quantum communication theory. Searching physically…

Quantum Physics · Physics 2018-12-18 Ming-Liang Hu , Xueyuan Hu , Jie-Ci Wang , Yi Peng , Yu-Ran Zhang , Heng Fan

Recently it has been shown how the use of quantum entanglement can lead to the creation of real-time communication channels whose viability can be made location dependent. Such functionality leads to new security paradigms that are not…

Quantum Physics · Physics 2016-09-12 Robert A Malaney

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

By using the Choi-Jamio{\l}kowski isomorphism, we propose two classes of coherence monotones of quantum channels based on the unified $(r,s)$-relative entropy and the sandwiched R\'{e}nyi relative entropy. Elegant properties of the…

Quantum Physics · Physics 2025-06-13 Jiaorui Fan , Zhaoqi Wu , Shao-Ming Fei

Decoherence in quantum bit circuits is presently a major limitation to their use for quantum computing purposes. We present experiments, inspired from NMR, that characterise decoherence in a particular superconducting quantum bit circuit,…

Superconductivity · Physics 2015-06-25 G. Ithier , E. Collin , P. Joyez , P. J. Meeson , D. Vion , D. Esteve , F. Chiarello , A. Shnirman , Y. Makhlin , J. Schriefl , G. Schon

The uncertainty relation reveals the intrinsic difference between the classical world and the quantum world. We investigate the quantum uncertainty relation of quantum channel in qubit systems. Under two general measurement bases, we first…

Quantum Physics · Physics 2024-09-02 Shi-Yun Kong , Ming-Jing Zhao , Zhi-Xi Wang , Shao-Ming Fei

We address the problem of the robustness of entanglement of bipartite systems (qubits) interacting with dynamically independent environments. In particular, we focus on characterization of so-called local entanglement-annihilating two-qubit…

Quantum Physics · Physics 2012-01-05 Sergey N. Filippov , Tomas Rybar , Mario Ziman

The maximum rates for information transmission through noisy quantum channels has primarily been developed for memoryless channels, where the noise on each transmitted state is treated as independent. Many real world communication channels…

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

By using the Choi-Jamio{\l}kowski isomorphism, we propose a well-defined coherence measure of quantum channels based on the generalized $\alpha$-$z$-relative R\'{e}nyi entropy. In addition, we present an alternative coherence measure of…

Quantum Physics · Physics 2025-06-13 Jiaorui Fan , Zhaoqi Wu , Shao-Ming Fei

This paper investigates properties of noisy quantum information channels. We define a new quantity called {\em coherent information} which measures the amount of quantum information conveyed in the noisy channel. This quantity can never be…

Quantum Physics · Physics 2009-10-30 Benjamin Schumacher , M. A. Nielsen

We provide a new way to bound the security of quantum key distribution using only two high-level, diagrammatic features of quantum processes: the compositional behavior of complementary measurements and the essential uniqueness of…

Quantum Physics · Physics 2017-07-20 Aleks Kissinger , Sean Tull , Bas Westerbaan

Despite being one of the hallmarks of quantum physics, there is a lack of operational interpretations of quantum coherence. Here we provide an operational interpretation of coherence of a quantum system, in terms of the amount of noise that…

Quantum Physics · Physics 2017-04-10 Uttam Singh , Manabendra Nath Bera , Avijit Misra , Arun Kumar Pati