title: Evading surface and detector frequency noise in harmonic oscillator measurements of force gradients.
abstract: We introduce and demonstrate a method of measuring small force gradients acting on a harmonic oscillator in which the force-gradient signal of interest is used to parametrically up-convert a forced oscillation below resonance into an amplitude signal at the oscillator's resonance frequency. The approach, which we demonstrate in a mechanically detected electron spin resonance experiment, allows the force-gradient signal to evade detector frequency noise by converting a slowly modulated frequency signal into an amplitude signal.
authors: Eric W
authors: EW
authors: Moore
authors: Sanggap
authors: S
authors: Lee
authors: Steven A
authors: SA
authors: Hickman
authors: Lee E
authors: LE
authors: Harrell
authors: John A
authors: JA
authors: Marohn