Efficient motional-mode characterization for high-fidelity trapped-ion quantum computing

TL;DR

This paper introduces a rapid and accurate method for characterizing motional modes in trapped-ion quantum computers, significantly reducing calibration time and enhancing system scalability.

Contribution

It develops physical models for predicting Lamb-Dicke parameters in parallel mode probing and proposes an advanced protocol that shortens characterization time by over tenfold.

Findings

Accurate prediction of Lamb-Dicke parameters in parallel mode probing

Characterization time reduced by more than an order of magnitude

Implications for scalable trapped-ion quantum computing

Abstract

To achieve high-fidelity operations on a large-scale quantum computer, the parameters of the physical system must be efficiently characterized with high accuracy. For trapped ions, the entanglement between qubits are mediated by the motional modes of the ion chain, and thus characterizing the motional-mode parameters becomes essential. In this paper, we develop and explore physical models that accurately predict both magnitude and sign of the Lamb-Dicke parameters when the modes are probed {\it in parallel}. We further devise an advanced characterization protocol that shortens the characterization time by more than an order of magnitude, when compared to that of the conventional method that only uses mode spectroscopy. We discuss potential ramifications of our results to the development of a scalable trapped-ion quantum computer, viewed through the lens of system-level resource trade offs.