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An Optimized Qubit for the Next Generation of Quantum Information: The A = 133 Isotope of Barium

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Technical Report,01 Jul 2015,31 Mar 2018

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University of California - San Diego La Jolla United States

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Among the atomic ions that could be used for quantum information storage and processing, barium-133, a man-made radioisotope, possesses several unique and desirable properties that are not found in any naturally occurring species. These properties combine to make it a nearly ideal qubit. Specifically, the barium electronic structure provides transitions in the visible part of the electromagnetic spectrum, enabling the use of the high-power lasers, low-loss fibers, high quantum efficiency detectors, and other optical equipment not available to ion species currently in use. The nuclear structure of barium-133 provides a robust hyperfine clock state qubit that is easy to initialize and detect, yet protects the qubit coherence during shuttling and storage. These features make it compatible with existing traps and in many ways superior to species currently in use, particularly for a QCCD architecture and for remote linking via photons. Under this program, we have developed techniques to load and cool 133Ba, as well as perform state initialization and state detection. We have also shown that the radioactivity of this isotope is a complication that can be dealt with in a way that is compatible with essentially all existing trapped ion quantum information processors, and is justified by the advantages of this species over the other ions in use.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy
  • Quantum Theory and Relativity

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