Errors in stimulated-Raman-induced logic gates in $^{133}$Ba$^+$

TL;DR

This paper measures spontaneous Raman scattering in ${}^{133}$Ba$^+$ ions driven by far-detuned lasers, showing the actual scattering rate is lower than previous estimates and challenging the assumed fundamental limits on laser-driven quantum gates.

Contribution

It provides a more accurate model of photon scattering in ${}^{133}$Ba$^+$, demonstrating no fundamental limit to laser-driven quantum gates from Raman scattering.

Findings

Measured lower-than-expected Raman scattering rates

Revised the theoretical model with better photon density of states

Showed no fundamental limit from Raman scattering on quantum gates

Abstract

${}^{133}\mathrm{Ba}^+$ is illuminated by a laser that is far-detuned from optical transitions, and the resulting spontaneous Raman scattering rate is measured. The observed scattering rate is lower than previous theoretical estimates. The majority of the discrepancy is explained by a more accurate treatment of the scattered photon density of states. This work establishes that, contrary to previous models, there is no fundamental limit to laser-driven quantum gates from laser-induced spontaneous Raman scattering.