Quantum operations in realistic neutral atom systems

In recent years, neutral atom arrays have emerged as one of the most promising platforms for quantum computation and simulation. In order to understand the current and future capabilities of these systems, it is important to employ numerical models which describe accurately detrimental effects on the fidelity of quantum operations such as decay of atomic states or laser phase noise. Here, we use efficient models that take into account these effects to study and optimize digital and analog operations in arrays of neutral atoms. Regarding digital gates, we present a robust protocol based on adiabatic rapid passage [1] for realizing high-fidelity multiqubit controlled phase gates. For currently available laser frequencies and powers, this scheme achieves fidelities F > 0.995 for three qubits and F > 0.99 for four qubits in ∼1.8 μs, with future technologies allowing access to higher fidelities. As for analog operations, we evaluate the impact of laser phase noise on the thermalization properties of adiabatically prepared crystalline states in one-dimensional neutral atom arrays.

[1] G. Pelegrí, A. J. Daley, and J. D. Pritchard, Quantum Science and Technology 7, 045020 (2022).