Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 24: Nanomechanics

TT 24.4: Vortrag

Mittwoch, 28. März 2012, 10:15–10:30, H 3005

Microwave cavity-enhanced transduction for plug and play nanomechanics at room temperature — •Thomas Faust, Peter Krenn, Stephan Manus, Jörg P. Kotthaus, and Eva M. Weig — Fakultät für Physik and Center for NanoScience, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539 München, Germany

The readout and manipulation of nanomechanical systems can be significantly enhanced by coupling them to an optical or electrical cavity. The latter has the advantage of allowing to read out a large array of resonators with only one cavity without any positioning involved. Up to now experiments employing the coupling to microwave cavities are performed at cryogenic temperatures to benefit from capacitively coupled superconducting cavities and resonators.

We present an approach based on a conventional λ/4 microstrip cavity at room temperature. It is dielectrically coupled to a doubly-clamped high stress silicon nitride beam with an extremely high mechanical quality factor of 290,000 at a mechanical resonance frequency of 6.6 MHz. Displacement detection is performed by monitoring the mechanically induced sidebands in the microwave cavity transmission signal. The sensitivity is sufficient to resolve the Brownian motion. Furthermore, the obtained coupling is strong enough to observe backaction effects of the microwave field on the mechanical resonator. We realise both cooling of the fundamental mode to 150 K as well as entering the regime of cavity-pumped self-oscillation. Thereby, an adjustement-free, all-integrated and self-driven resonator interfaced by just two microwave connectors is realised.