Multidimensional optomechanical cantilevers for high frequency atomic force microscopy

TL;DR

This paper introduces high-frequency nanomechanical cantilevers with optomechanical detection that surpass traditional limits, enabling ultra-sensitive, multidimensional force measurements for advanced atomic force microscopy.

Contribution

The work demonstrates the first use of optomechanical detection on high-frequency nanocantilevers up to 20 MHz, achieving unprecedented force sensitivity and multidimensional motion resolution.

Findings

Achieved 2 fm/√Hz displacement noise floor

Force sensitivity down to 132 aN/√Hz

Enabled in situ tuning of cantilever frequency

Abstract

High-frequency atomic force microscopy has enabled extraordinary new science through large bandwidth, high speed measurements of atomic and molecular structures. However, traditional optical detection schemes restrict the dimensions, and therefore the frequency, of the cantilever - ultimately setting a limit to the time resolution of experiments. Here we demonstrate optomechanical detection of low-mass, high-frequency nanomechanical cantilevers (up to 20 MHz) that surpass these limits, anticipating their use for single-molecule force measurements. These cantilevers achieve 2 fm / sqrt(Hz) displacement noise floors, and force sensitivity down to 132 aN / sqrt(Hz). Furthermore, the ability to resolve both in-plane and out-of-plane motion of our cantilevers opens the door for ultrasensitive multidimensional force spectroscopy, and optomechanical interactions, such as tuning of the cantilever frequency in situ, provide new opportunities in high-speed, high-resolution experiments.