  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.
