Thermal nonlinearities in a nanomechanical oscillator

By Lukás Novotný, R. Quidant. Nature Physics, 2013

269 citations recorded by the source corpus.

Nano- and micromechanical oscillators with high quality (Q)-factors have gained much attention for their potential application as ultrasensitive detectors. In contrast to micro-fabricated devices, optically trapped nanoparticles in vacuum do not suffer from clamping losses, hence leading to much larger Q-factors. We find that for a levitated nanoparticle the thermal energy suffices to drive the motion of the nanoparticle into the nonlinear regime. First, we experimentally measure and fully characterize the frequency fluctuations originating from thermal motion and nonlinearities. Second, we demonstrate that feedback cooling can be used to mitigate these fluctuations. The high level of control allows us to fully exploit the force-sensing capabilities of the nanoresonator. Our approach offers a force sensitivity of 20 zN Hz−1/2, which is the highest value reported so far at room temperature, sufficient to sense ultraweak interactions, such as non-Newtonian gravity-like forces. A room-temperature motion sensor with record sensitivity is created using a levitating silica nanoparticle. Feedback cooling to reduce the noise arising from Brownian motion enables a detector that is perhaps even sensitive enough to detect non-Newtonian gravity-like forces.

Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/89365925acb38e6306477745103cf0fd8b49bd70