Frequency stability is key to performance of nanoresonators. This stability is thought to reach a limit with the resonator's ability to resolve thermally-induced vibrations. Although measurements and predictions of resonator stability usually disregard fluctuations in the mechanical frequency response, these fluctuations have recently attracted considerable theoretical interest. However, their existence is very difficult to demonstrate experimentally. Here, through a literature review, we show that all studies of frequency stability report values several orders of magnitude larger than the limit imposed by thermomechanical noise. We studied a monocrystalline silicon nanoresonator at room temperature, and found a similar discrepancy. We propose a new method to show this was due to the presence of frequency fluctuations, of unexpected level. The fluctuations were not due to the instrumentation system, or to any other of the known sources investigated. These results challenge our current understanding of frequency fluctuations and call for a change in practices.
@article{arxiv.1506.08135,
title = {Frequency fluctuations in silicon nanoresonators},
author = {Marc Sansa and Eric Sage and Elizabeth C. Bullard and Marc Gély and Thomas Alava and Eric Colinet and Akshay K. Naik and Luis Guillermo Villanueva and Laurent Duraffourg and Michael L. Roukes and Guillaume Jourdan and Sébastien Hentz},
journal= {arXiv preprint arXiv:1506.08135},
year = {2016}
}