We demonstrate a simple pulse shaping technique designed to improve the fidelity of spin-dependent force operations commonly used to implement entangling gates in trapped-ion systems. This extension of the M{\o}lmer-S{\o}rensen gate can theoretically suppress the effects of certain frequency and timing errors to any desired order and is demonstrated through Walsh modulation of a two-qubit entangling gate on trapped atomic ions. The technique is applicable to any system of qubits coupled through collective harmonic oscillator modes.
@article{arxiv.1104.1347,
title = {Coherent Error Suppression in Multi-Qubit Entangling Gates},
author = {D. Hayes and S. M. Clark and S. Debnath and D. Hucul and I. V. Inlek and K. W. Lee and Q. Quraishi and C. Monroe},
journal= {arXiv preprint arXiv:1104.1347},
year = {2013}
}