THE EFFECT OF THE CENTER-OF-MASS MOTION ON THE FIDELITY OF NEUTRAL-ATOM QUANTUM GATES AND THE OPTIMAL CIRCUIT FOR A PROTECTED QUBIT

Abstract

In the first part, we study the effects of the center-of-mass (CM) motion on Raman transitions. Theoretical and experimental values of the fidelities of two-qubit neutral-atom gates suffer significant disagreement. This suggests that a more thorough analysis on the possible errors in the implementation of the gates is needed. We find that there is a strong correlation between the CM motion and the fidelity of the gate. We also demonstrate the previous discrepancies between theoretical and experimental results in the robustness analysis for a control-phase gate, which can be resolved by considering the effects of the CM motion. In the second part, we study the optimal circuit for the decoherence-free memory scheme of R. Han's PhD thesis on 2012. We are able to find a circuit that contains fewer single-qubit gates than the existing optimal scheme. Finally, we use the Monte Carlo method to show the robustness of the circuit under general noise.