Abstract
We propose an optical scheme for generating entanglement between co-trapped identical or dissimilar alkaline-earth atomic ions (, , , ) which exhibits fundamental error rates below and can be implemented with a broad range of laser wavelengths spanning from ultraviolet to infrared. We also discuss straightforward extensions of this technique to include the two lightest group-2 ions (, ) for multispecies entanglement. The key elements of this wavelength-insensitive geometric phase gate are the use of a ground () and a metastable () electronic state as the qubit levels within a light-shift entangling gate. We present a detailed analysis of the principles and fundamental error sources for this gate scheme which includes photon scattering and spontaneous emission decoherence, calculating two-qubit-gate error rates and durations at fixed laser beam intensity over a large portion of the optical spectrum (300 nm to ) for an assortment of ion pairs. We contrast the advantages and disadvantages of this technique against previous trapped-ion entangling gates and discuss its applications to quantum information processing and simulation with like and multispecies ion crystals.
- Received 9 October 2020
- Accepted 27 January 2021
DOI:https://doi.org/10.1103/PhysRevA.103.022427
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