Thursday, 15 October, 2009

Quantum-limited measurement method for nanosensors

New fabrication techniques have enabled the development of on-chip mechanical elements whose dimensions are on the nanometre (one millionth mm) scale. Their application, however, has been limited by the lack of sufficiently sensitive techniques for measuring the motion of these tiny devices. A team of scientists around Professor Tobias Kippenberg (Leader of the Independent Junior Research Group Laboratory of Photonics and Quantum Measurements at the Max Planck Institute of Quantum Optics in Garching and Tenure Track Assistant Professor at the EPFL Lausanne) and Professor Jörg Kotthaus (Professor at LMU Munich) has now successfully developed a novel method. On-chip glass cylinders with diameters around 50 microns which are capable of storing light played a key role in the study. The scientists could show that the optical near-field, that is the light-field that is leaking out of the glass cylinders, can be used as actuator and sensitive probe for nanomechanical oscillators. This enables measurements that are only limited by the fundamental quantum fluctuations of light. Thereby, the novel technique for the first time allows measurement sensitivities at the level of the quantum mechanical zero-point fluctuations of the nano-oscillators which is of great interest for fundamental research. But also applications such as single-atom or single-charge detection by atomic or magnetic force microscopy may benefit from the extremely low-noise method with a noise background at the level of the standard quantum-limit. (...)

Press information LMU (english)
Presseinformation der LMU (deutsch)
Publication: "Near-field cavity optomechanics with nanomechanical oscillators"