Spatially resolved surface dissipation over metal and dielectric substrates

TL;DR

This study uses a nanoladder cantilever to spatially map static and fluctuating electric fields over metal and dielectric surfaces, revealing surface dissipation effects relevant to various quantum and sensing technologies.

Contribution

It provides the first spatially resolved measurements linking surface charge and dielectric fluctuations to dissipation on conductive and dielectric surfaces.

Findings

Static and fluctuating fields are spatially correlated and similar in magnitude for Au and SiO2.

Surface dissipation is driven by trapped charges and dielectric fluctuations in adsorbates.

Results impact understanding of noise sources in nanomechanical sensors and quantum devices.

Abstract

We report spatially resolved measurements of static and fluctuating electric fields over conductive (Au) and non-conductive (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 that the two quantities are spatially correlated and 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 provide direct, spatial evidence for surface dissipation in adsorbates that affects nanomechanical sensors, trapped ions, superconducting resonators, and color centers in diamond.