  High-stress silicon nitride nanostrings are a promising system for sensing
applications because of their ultra-high mechanical quality factors (Qs). By
performing thermomechanical calibration across multiple vibrational modes, we
are able to assess the roles of the various dissipation mechanisms in these
devices. Specifically, we possess a set of nanostrings in which all measured
modes fall upon a single curve of peak displacement versus frequency. This
allows us to rule out bulk bending and intrinsic loss mechanisms as dominant
sources of dissipation and to conclude that the most significant contribution
to dissipation in high-stress nanostrings occurs at the anchor points.
