Temperature-Dependent Nonlinear Damping in Palladium Nanomechanical Resonators

Advances in nano-fabrication techniques has made it feasible to observe damping phenomena beyond the linear regime nano-mechanical systems. In this work, we report cubic non-linear palladium resonators. Nano-scale beams exposed a $H_2$ atmosphere become softer and display enhanced Duffing non-linearity as well at ultra low temperatures. The is highest lowest temperatures of $\sim 110\: mK$ decreases when warmed up-to 1\textrm{ }K$. We experimentally demonstrate for first time temperature dependent system below 1 K. It consistent with predicted two phonon mediated Akhiezer scenario ballistic phonons mean free path comparable beam thickness. This opens up new possibilities engineer