Accurate Microwave Control and Real-Time Diagnostics of Neutral Atom Qubits

TL;DR

This paper demonstrates high-fidelity single-qubit control of neutral atom qubits using microwave radiation, with real-time diagnostics and composite rotations to improve robustness, achieving 0.99 fidelity in optical lattice experiments.

Contribution

It introduces a method for accurate microwave control and real-time diagnostics of neutral atom qubits, enhancing gate fidelity and robustness.

Findings

Achieved 0.99 fidelity for single-qubit pi rotations.

Real-time optical polarimetry enables effective diagnostics.

Composite rotations increase robustness to errors.

Abstract

We demonstrate accurate single-qubit control in an ensemble of atomic qubits trapped in an optical lattice. The qubits are driven with microwave radiation, and their dynamics tracked by optical probe polarimetry. Real-time diagnostics is crucial to minimize systematic errors and optimize the performance of single-qubit gates, leading to fidelities of 0.99 for single-qubit pi rotations. We show that increased robustness to large, deliberately introduced errors can be achieved through the use of composite rotations. However, during normal operation the combination of very small intrinsic errors and additional decoherence during the longer pulse sequences precludes any significant performance gain in our current experiment.