Comparison of Gaussian and super Gaussian laser beams for addressing atomic qubits

TL;DR

This study compares Gaussian and super Gaussian laser beams for atomic qubit control, demonstrating that super Gaussian beams significantly improve gate fidelity by reducing sensitivity to motion and misalignment.

Contribution

It introduces a numerical analysis showing super Gaussian beams with n=6 outperform Gaussian beams in atomic qubit gate fidelity and crosstalk reduction.

Findings

Super Gaussian beams with n=6 increase Rabi oscillation decay time by 60x.

Super Gaussian beams reduce sensitivity to atomic motion and beam misalignment.

Improved gate fidelity and reduced crosstalk with super Gaussian modes.

Abstract

We study the fidelity of single qubit quantum gates performed with two-frequency laser fields that have a Gaussian or super Gaussian spatial mode. Numerical simulations are used to account for imperfections arising from atomic motion in an optical trap, spatially varying Stark shifts of the trapping and control beams, and transverse and axial misalignment of the control beams. Numerical results that account for the three dimensional distribution of control light show that a super Gaussian mode with intensity $I\sim e^{-2(r/w_0)^n}$ provides reduced sensitivity to atomic motion and beam misalignment. Choosing a super Gaussian with $n=6$ the decay time of finite temperature Rabi oscillations can be increased by a factor of 60 compared to an $n=2$ Gaussian beam, while reducing crosstalk to neighboring qubit sites.