Entanglement generation in trapped-ion systems has relied thus far on two distinct but related geometric phase gate techniques: Molmer-Sorensen and light-shift gates. We recently proposed a variant of the light-shift scheme where the qubit levels are separated by an optical frequency [B. C. Sawyer and K. R. Brown, Phys. Rev. A 103, 022427 (2021)]. Here we report an experimental demonstration of this entangling gate using a pair of 40Ca+ ions in a cryogenic surface-electrode ion trap and a commercial, high-power, 532 nm Nd:YAG laser. Generating a Bell state in 35 μs, we directly measure an infidelity of 6(3)×10−4 without subtraction of experimental errors. The 532 nm gate laser wavelength suppresses intrinsic photon scattering error to ∼1×10−5.
@article{arxiv.2105.05828,
title = {High-Fidelity Bell-State Preparation with $^{40}$Ca$^+$ Optical Qubits},
author = {Craig R. Clark and Holly N. Tinkey and Brian C. Sawyer and Adam M. Meier and Karl A. Burkhardt and Christopher M. Seck and Christopher M. Shappert and Nicholas D. Guise and Curtis E. Volin and Spencer D. Fallek and Harley T. Hayden and Wade G. Rellergert and Kenton R. Brown},
journal= {arXiv preprint arXiv:2105.05828},
year = {2021}
}
Comments
7 pages, 6 figures, should match published version