Greenberger-Horne-Zeilinger state protocols for fully connected qubit networks

Journal Article · Tue Dec 15 04:00:00 EST 2009 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.80.062302· OSTI ID:21352302

Galiautdinov, Andrei; Coffey, Mark W; Deiotte, Ron ^[1]

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1. Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602 (United States)

We generalize the recently proposed Greenberger-Horne-Zeilinger tripartite protocol [A. Galiautdinov and J. M. Martinis, Phys. Rev. A 78, 010305(R) (2008)] to fully connected networks of weakly coupled qubits interacting by way of anisotropic Heisenberg exchange g(XX+YY)+g-tildeZZ. Our model differs from the more familiar Ising-Heisenberg chain in that here every qubit interacts with every other qubit in the circuit. The assumption of identical couplings on all qubit pairs allows an elegant proof of the protocol for arbitrary N. In order to further make contact with experiment, we study fidelity degradation due to coupling imperfections by numerically simulating the N=3 and 4 cases. Our simulations indicate that the best fidelity at unequal couplings is achieved when (a) the system is initially prepared in the uniform superposition state (similarly to how it is done in the ideal case) and (b) the entangling time and the final rotations on each of the qubits are appropriately adjusted.

• OSTI ID: 21352302
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 80; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
COMPUTERS
CRYSTAL MODELS
ELECTRONS
ELEMENTARY PARTICLES
EXCHANGE INTERACTIONS
FERMIONS
HEISENBERG MODEL
INFORMATION
INTERACTIONS
ISING MODEL
LEPTONS
MATHEMATICAL MODELS
MATHEMATICS
NUMERICAL ANALYSIS
QUANTUM COMPUTERS
QUANTUM ENTANGLEMENT
QUANTUM INFORMATION
QUBITS
SIMULATION