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Q: Fachverband Quantenoptik und Photonik
Q 57: Micromechanical Oscillators II
Q 57.3: Vortrag
Freitag, 12. März 2010, 11:00–11:15, A 320
Cavity-Optomechanics with Silica Microresonators at Helium-3 Temperatures — •Stefan Weis1, Rémi Rivière1, Olivier Arcizet1,2, Albert Schliesser1, Samuel Deléglise1, Emanuel Gavartin3, and Tobias J. Kippenberg1,3 — 1MPI für Quantenoptik, 85748 Garching, Germany — 2Institut Néel, CNRS, 38042 Grenoble, France — 3Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
We present the optical and mechanical properties of toroidal resonators thermalized to Helium-3 (600 mK) temperatures, which exhibit ultrahigh optical Q (up to 108) whispering gallery mode resonances coupled via radiation pressure to mechanical radial breathing modes.
Recent experiments performed in a Helium-4 cryostat aiming at ground state cooling the mechanical degree of freedom have combined cryogenic precooling with laser cooling. Final phonon occupation numbers of about 60 quanta [1] could be attained, which were however limited by the mechanical losses due to two-level systems at temperatures above 1.6 K. Here, we demonstrate that the mechanical Q dramatically improves at temperatures below 1 K, enabling mechanical Q factor in excess of 10,000.
The large achievable mechanical Q factors, combined with low initial occupancies of <200 for 75 MHz oscillators, render this system a promising candidate for ground state cooling and a range of experiments pertaining to quantum measurement theory of mechanical oscillators.
[1] A. Schliesser et al., Nature Physics 5, 509 (2009)