Publications Charles FROMONTEIL

2024

C. Fromonteil, R. Tricarico, F. Cesa, H. Pichler Hamilton-Jacobi-Bellman equations for Rydberg-blockade processes, Phys. Rev. Research 6 33333 (2024-09-24), http://dx.doi.org/10.1103/PhysRevResearch.6.033333 doi:10.1103/PhysRevResearch.6.033333 (ID: 721246) Toggle Abstract
We discuss time-optimal control problems for two setups involving globally driven Rydberg atoms in the blockade limit by deriving the associated Hamilton-Jacobi-Bellman equations. From these equations, we extract the globally optimal trajectories and the corresponding controls for several target processes of the atomic system, using a generalized method of characteristics. We apply this method to retrieve known results for CZ and C-phase gates, and to find new optimal pulses for all elementary processes involved in the universal quantum computation scheme introduced in [Physical Review Letters 131, 170601 (2023)].

C. Fromonteil, D. Bluvstein, H. Pichler Protocols for Rydberg entangling gates featuring robustness against quasi-static errors, PRX Quantum 4 (2023-06-05), http://dx.doi.org/10.1103/PRXQuantum.4.020335 doi:10.1103/PRXQuantum.4.020335 (ID: 720959) Toggle Abstract
We introduce a novel family of protocols for entangling gates for neutral atom qubits based on the Rydberg blockade mechanism. These protocols realize controlled-phase gates through a series of global laser pulses that are on resonance with the Rydberg excitation frequency. We analyze these protocols with respect to their robustness against calibration errors of the Rabi frequency or shot-to-shot laser intensity fluctuations, and show that they display robustness in various fidelity measures. In addition, we discuss adaptations of these protocols in order to make them robust to atomic-motion-induced Doppler shifts as well.