arXiv:1808.03473 · Physical Review A
Fast three-qubit Toffoli quantum gate based on three-body Förster resonances in Rydberg atoms
Ilya I. Beterov, I. N. Ashkarin, Elena A. Yakshina, Denis B. Tretyakov, Vasily M. Entin, I. I. Ryabtsev, Patrick Cheinet, P. Pillet, Mark E. Saffman
Abstract
We propose a scheme of fast three-qubit Toffoli quantum gate for ultracold neutral-atom qubits. The scheme is based on Stark-tuned three-body F\"orster resonances, which we have observed in our recent experiment [D. B. Tretyakov et al., Phys. Rev. Lett. 119, 173402 (2017)]. The three-body resonance corresponds to a transition when the three interacting atoms change their states simultaneously, and it occurs at a different dc electric field with respect to the two-body F\"orster resonance. A combined effect of three-body and two-body F\"orster interactions in external electric and magnetic fields near the three-body resonance results in complex coherent behavior of the populations and phases of collective states of a three-atom system. We have found that it is possible to obtain experimental conditions suitable to implement three-qubit Toffoli gate with 98.3% fidelity and less than 3 $\ensuremath{\mu}\mathrm{s}$ duration.