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Related papers: Effect of Decoherence in Ekert-Protocol

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Shared entanglement can significantly amplify classical correlations between systems interacting over a limited quantum channel. A natural avenue is to use entanglement of the same dimension as the channel because this allows for unitary…

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

Elucidating the emergence of irreversible macroscopic laws from reversible quantum many-body dynamics is a question of broad importance across all quantum science. Many-body decoherence plays a key role in this transition, yet connecting…

Quantum Physics · Physics 2025-11-12 Cooper M. Selco , Christian Bengs , Chaitali Shah , Zhuorui Zhang , Ashok Ajoy

Effect of quantum decoherence in a three-player quantum Kolkata restaurant problem is investigated using tripartite entangled qutrit states. Amplitude damping, depolarizing, phase damping, trit-phase flip and phase flip channels are…

Quantum Physics · Physics 2013-01-15 M. Ramzan

We analyze how decoherence appears in the I-V characteristics of a voltage-biased single-Cooper-pair transistor. Especially the effect on resonant single or several Cooper-pair tunneling is studied. We consider both a symmetric and an…

Superconductivity · Physics 2008-11-07 J. Leppäkangas , E. Thuneberg

Large-scale quantum systems require optical coherence between distant quantum devices, necessitating spectral indistinguishability. Scalable solid-state platforms offer promising routes to this goal. However, environmental disorders,…

We study decoherence of two non-interacting qubits. The environment and its interaction with the qubits are modelled by random matrices. Decoherence, measured in terms of purity, is calculated in linear response approximation. Monte Carlo…

Quantum Physics · Physics 2007-11-22 C. Pineda , T. Gorin , T. H. Seligman

In this work we derive analytical relations between Entanglement and Coherence as well as between Discord and Coherence, for Bell-diagonal states and for X states, evolving under the action of several noise channels: Bit Flip, Phase Damping…

Quantum Physics · Physics 2020-11-12 J. D. Young , A. Auyuanet

We analyze the notion of quantum coherence in an interference experiment. We let the phase shifts fluctuate according to a given statistical distribution and introduce a decoherence parameter, defined in terms of a generalized visibility of…

Quantum Physics · Physics 2010-01-31 A. Mariano , P. Facchi , S. Pascazio

In quantum error correction, the description of noise channel cannot be completely accurate, and fluctuation always appears in noise channel. It is found that when fluctuation of physical noise channel is considered, the average effective…

Quantum Physics · Physics 2019-10-30 Long Huang , Xiaohua Wu , Tao Zhou

We calculate the dissipative dynamics of two-qubit quantum discord under Markovian environments. We analyze various dissipative channels such as dephasing, depolarizing, and generalized amplitude damping, assuming independent perturbation,…

Quantum Physics · Physics 2009-09-16 T. Werlang , S. Souza , F. F. Fanchini , C. J. Villas-Boas

We analyse dissipation in quantum computation and its destructive impact on efficiency of quantum algorithms. Using a general model of decoherence, we study the time evolution of a quantum register of arbitrary length coupled with an…

Quantum Physics · Physics 2015-06-26 G. Massimo Palma , Kalle-Antti Suominen , Artur K. Ekert

The coherence time of an electron spin decohered by the nuclear spin environment in a quantum dot can be substantially increased by subjecting the electron to suitable dynamical decoupling sequences. We analyze the performance of high-level…

Mesoscale and Nanoscale Physics · Physics 2008-03-27 Wenxian Zhang , N. P. Konstantinidis , V. V. Dobrovitski , B. N. Harmon , Lea F. Santos , Lorenza Viola

We study the effects of decoherence in the form of optical phase diffusion, photon loss and gain, and atomic dephasing in entangled atomic ensembles produced via quantum nondemolition (QND) measurements. For the optical decoherence…

The Ekert 91 quantum key distribution (QKD) protocol appears to be secure whatever devices legitimate users adopt for the protocol, as long as the devices give a result that violates Bell's inequality. However, this is not the case if they…

Quantum Physics · Physics 2009-11-11 W. -Y. Hwang

The total correlations in a bipartite quantum system are measured by the quantum mutual information $\mathcal{I}$, which consists of quantum discord and classical correlation. However, recent results in quantum information shows that…

Quantum Physics · Physics 2017-10-25 Jin-Xing Hou , Si-Yuan Liu , Xiao-Hui Wang , Wen-Li Yang

We report on a complete free-space field implementation of a modified Ekert91 protocol for quantum key distribution using entangled photon pairs. For each photon pair we perform a random choice between key generation and a Bell inequality.…

In this paper, we investigate the cohering and decohering power for the one-qubit Markovian channels with respect to coherence in terms of the $l_{1}$-norm, the R$\acute{e}$nyi $\alpha$-relative entropy and the Tsallis $\alpha$-relative…

Quantum Physics · Physics 2017-12-06 Ming-Ming Chen , Yu Luo , Lian-He Shao , Yong-Ming Li

This is the first in a series of two papers (I and II), in which we revisit the problem of decoherence in weak localization. The basic challenge addressed in our work is to calculate the decoherence of electrons interacting with a…

Disordered Systems and Neural Networks · Physics 2007-12-02 Florian Marquardt , Jan von Delft , R. A. Smith , Vinay Ambegaokar

We consider the decoherence of photons suffering in phase-damping channels. By exploring the evolutions of single-photon polarization states and two-photon polarization-entangled states, we find that different frequency spectrum envelopes…

Quantum Physics · Physics 2008-10-08 Yan-Xiao Gong , Yong-Sheng Zhang , Yu-Li Dong , Xiao-Ling Niu , Yun-Feng Huang , Guang-Can Guo
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