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Tunable spin-spin interactions and entanglement of ions in separate controlled potential wells



Andrew C. Wilson, Yves Colombe, K. R. Brown, Emanuel H. Knill, Dietrich G. Leibfried, David J. Wineland


Inspired by the ideas of Richard Feynman,1 David Deutsch,2 Seth Lloyd3 and others, researchers in the field of quantum information processing and simulation seek to harness the quantum-mechanical properties of well-controlled laboratory systems to perform otherwise intractable computations and quantum simulations. Physical systems that cannot be modeled with classical computers appear in many different branches of science, including condensed-matter physics, statistical mechanics, highenergy physics, atomic physics and quantum chemistry. Despite impressive progress on the control and manipulation of various quantum systems,4, 5 implementation of scalable devices for quantum simulation remains a formidable challenge.6 For largescale universal quantum computing the technical demands are even greater. As one approach to scalability in simulation, here we demonstrate an elementary buildingblock of a configurable quantum simulator based on atomic ions.7 Two ions are trapped in separate potential wells that can individually be tailored to emulate a number of different spin-spin couplings mediated by the ions' Coulomb interaction together with classical laser and microwave fields. We demonstrate deterministic tuning of this interaction by independent control of the local wells and emulate a particular spin-spin interaction to entangle the internal states of the two ions with 0.81(2) fidelity. Extension of the building-block demonstrated here to a 2D-network,8-10 which iontrap micro-fabrication processes enable, may provide a new quantum simulator architecture with broad flexibility in designing and scaling the arrangement of ions and their mutual interactions. This 'bottom-up' approach complements the 'top-down' strategy to quantum simulation adopted with ultracold quantum gases.11


Quantum simulation, quantum information processing, quantum entanglement, trapped atomic ions


Wilson, A. , Colombe, Y. , Brown, K. , Knill, E. , Leibfried, D. and Wineland, D. (2014), Tunable spin-spin interactions and entanglement of ions in separate controlled potential wells, Nature, [online], (Accessed May 28, 2024)


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Created August 7, 2014, Updated February 19, 2017