Control of quantum systems and inherent robustness to field fluctuations

A relationship is shown to exist between optimally controlled quantum dynamics and field fluctuations, wherein the process of seeking optimal performance assures an inherent degree of system robustness to such fluctuations. Robustness occurs because the optimization process reduces sensitivity to noise-driven quantum system fluctuations by taking advantage of the observable expectation value being bilinear in the evolution operator and its adjoint. The consequences of this inherent robustness are discussed in light of recent experiments and numerical simulations on optimal control of quantum phenomena.