Berlin 2014 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 33: Micromechanical oscillators
Q 33.7: Talk
Thursday, March 20, 2014, 12:00–12:15, DO24 1.101
Thermal nonlinearities in a nanomechanical oscillator — •Jan Gieseler1, Lukas Novotny2, and Romain Quidant1,3 — 1ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain — 2Photonics Laboratory, ETH Zürich, 8093 Zürich, Switzerland — 3ICREA-Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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 to date at room temperature, sufficient to sense ultra-weak interactions, such as non-Newtonian gravity-like forces.