Search results for "QUANTUM CLONING"

showing 4 items of 4 documents

Cloning transformations in spin networks without external control

2004

In this paper we present an approach to quantum cloning with unmodulated spin networks. The cloner is realized by a proper design of the network and a choice of the coupling between the qubits. We show that in the case of phase covariant cloner the XY coupling gives the best results. In the 1->2 cloning we find that the value for the fidelity of the optimal cloner is achieved, and values comparable to the optimal ones in the general N->M case can be attained. If a suitable set of network symmetries are satisfied, the output fidelity of the clones does not depend on the specific choice of the graph. We show that spin network cloning is robust against the presence of static imperfection…

PhysicsQuantum PhysicsCondensed Matter - Mesoscale and Nanoscale Physicsmedia_common.quotation_subjectFidelityFOS: Physical sciencesQuantum PhysicsTopologyAtomic and Molecular Physics and OpticsQuantum gateAtomic and Molecular PhysicsQuantum mechanicsQubitMesoscale and Nanoscale Physics (cond-mat.mes-hall)Spin networkand OpticsQuantum cloningQuantum informationQuantum information scienceQuantum Physics (quant-ph)Quantum computermedia_common
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Effects of noise on spin network cloning

2006

We analyze the effects of noise on quantum cloning based on the spin network approach. A noisy environment interacting with the spin network is modeled both in a classical scenario, with a classical fluctuating field, and in a fully quantum scenario, in which the spins are coupled with a bath of harmonic oscillators. We compare the realization of cloning with spin networks and with traditional quantum gates in the presence of noise, and show that spin network cloning is more robust.

PhysicsQuantum networkQuantum informationPhysics and Astronomy (miscellaneous)Quantum cloning; Quantum information; Spin networks; Physics and Astronomy (miscellaneous)Open quantum systemQuantum gateQuantum error correctionQuantum mechanicsCondensed Matter::Strongly Correlated ElectronsQuantum algorithmSpin networkQuantum informationQuantum cloningQuantum cloningSpin networks
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Quantum cloning in spin networks

2004

We introduce an approach to quantum cloning based on spin networks and we demonstrate that phase covariant cloning can be realized using no external control but only with a proper design of the Hamiltonian of the system. In the 1 -> 2 cloning we find that the XY model saturates the value for the fidelity of the optimal cloner and gives values comparable to it in the genera N -> M case. We finally discuss the effect of external noise. Our protocol is much more robust to decoherence than a conventional procedure based on quantum gates.

PhysicsQuantum opticsQuantum PhysicsQuantum decoherenceCondensed Matter - Mesoscale and Nanoscale PhysicsFOS: Physical sciencesAtomic and Molecular Physics and Optics; Physics and Astronomy (all)Quantum PhysicsQuantum numberAtomic and Molecular Physics and Opticssymbols.namesakePhysics and Astronomy (all)Quantum mechanicsAtomic and Molecular PhysicsMesoscale and Nanoscale Physics (cond-mat.mes-hall)symbolsSpin networkQuantum cloningand OpticsHamiltonian (quantum mechanics)Quantum information scienceQuantum Physics (quant-ph)Quantum
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Information-flux approach to multiple-spin dynamics

2007

We introduce and formalize the concept of information flux in a many-body register as the influence that the dynamics of a specific element receive from any other element of the register. By quantifying the information flux in a protocol, we can design the most appropriate initial state of the system and, noticeably, the distribution of coupling strengths among the parts of the register itself. The intuitive nature of this tool and its flexibility, which allow for easily manageable numerical approaches when analytic expressions are not straightforward, are greatly useful in interacting many-body systems such as quantum spin chains. We illustrate the use of this concept in quantum cloning an…

PhysicsUNIVERSALQuantum networkQuantum PhysicsQuantum dynamicsFOS: Physical sciencesQuantum channelMathematical Physics (math-ph)Atomic and Molecular Physics and OpticsCondensed Matter - Other Condensed MatterOpen quantum systemQUANTUM CLONINGQuantum processQuantum mechanicsSTATE TRANSFERStatistical physicsCHAINSQuantum informationQuantum cloningQuantum information scienceQuantum Physics (quant-ph)Mathematical PhysicsOther Condensed Matter (cond-mat.other)
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