Ground state cooling and quantum backaction of a mechanical oscillator - GSC

• Applicant: Professor Dr. Tobias Kippenberg
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2008 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 61069054

The proposed research program builds on the previously developed ultra-high-Q monolithic micro-resonators by the applicant during his dissertation at the “California Institute of Technology”. These micro-resonators offer unprecedented confinement of light in microscale volumes for extended amounts of time and have opened many lab-on-chip applications ranging from nonlinear optics, quantum optic to biochemical sensing. This present proposal is concerned to use ultra-high-Q optical micro-cavities as vehicles to demonstrate cooling of a mechanical oscillator to its quantum ground state. So far ground state cooling of mechanical objects has inspired researchers for decades, but it has to date never been attained. Within the last year, several groups (including the applicants group at the MPQ in Garching) have demonstrated for the first time radiation pressure (laser) cooling of micro-mechanical oscillators. Only shortly after publication several other groups reported cooling of gram-scale mirrors and cantilevers using radiation pressure which has lead to a renewed effort towards achieving ground state cooling (GSC) of a mechanical oscillator, as summarized in figure 1. This proposal requests essential infrastructure in terms of low temperature equipment and a laser system - not presently covered under any other grant – to allow pursuing this goal at the Max Planck Institute of Quantum Optics and to keep pace with this rapidly moving international field. This research could result in the first demonstration of ground state cooling of a macroscopic object with ~1022 atoms, which has so far never been demonstrated as well as the first demonstration of pondermotive quantum back-action and squeezing. From a conceptual point of view, this research could show how a mechanical, macroscopic object reveals quantum mechanical behavior which could open the possibility to study the classical quantum boundary, or prepare non-classical states of mechanical motion.

• DFG Programme: Research Grants
• Major Instrumentation: 6-W Verdi Pump Laser System ; Liquid Helium Bath-Cryostat with Exchange Gas Cooling ; Ti:Sa Single Frequency Laser System
• Instrumentation Group: 5700 Festkörper-Laser