Surface Two-level State Dissipation in Single-Crystalline Gold Nanomechanical Resonators

Abstract

We study the intrinsic dissipation in nanomechanical resonators fabricated with synthetic singlecrystalline gold nanowires. Contrary to the etched nanostructures, the measured resonance frequencies and damping rates unambiguously demonstrate temperature dependence, as predicted by the standard two-level tunneling-state (TLS) theory. We compare the data to a model assuming a thin amorphous layer on the nanowire surface. The deduced TLS parameters are consistent with bulk poly(methyl methacrylate) (PMMA) data, confirming the presence of residual PMMA on the surface as the TLS host.