Spatial Correlation between Fluctuating and Static Fields over Metal and Dielectric Substrates

We report spatially resolved measurements of static and fluctuating electric fields over conductive (Au) and nonconductive (SiO2) surfaces. Using an ultrasensitive nanoladder cantilever probe to scan over these surfaces at distances of a few tens of nanometers, we record changes in the probe resonance frequency and damping that we associate with static and fluctuating fields, respectively. We find static and fluctuating fields to be spatially correlated. Furthermore, the fields are of similar magnitude for the two materials. We quantitatively describe the observed effects on the basis of trapped surface charges and dielectric fluctuations in an adsorbate layer. Our results are consistent with organic adsorbates significantly contributing to surface dissipation that affects nanomechanical sensors, trapped ions, superconducting resonators, and color centers in diamond.

Automated summary

This study reports spatially resolved measurements of static and fluctuating electric fields over conductive and nonconductive surfaces, revealing their spatial correlation and similar magnitudes for the two materials. The observed effects are quantitatively described based on trapped surface charges and dielectric fluctuations in an adsorbate layer, with implications for various applications involving surface dissipation.