Cooling-by-measurement and mechanical state tomography via pulsed optomechanics

Author(s)
M. R. Vanner, Joachim Hofer, G. D. Cole, M. Aspelmeyer
Abstract

Observing a physical quantity without disturbing it is a key capability for the control of individual quantum systems. Such back-action-evading or quantum non-demolition measurements were first introduced in the 1970s for gravitational wave detection, and now such techniques are an indispensable tool throughout quantum science. Here we perform measurements of the position of a mechanical oscillator using pulses of light with a duration much shorter than a period of mechanical motion. Utilizing this back-action-evading interaction, we demonstrate state preparation and full state tomography of the mechanical motional state. We have reconstructed states with a position uncertainty reduced to 19 pm, limited by the quantum fluctuations of the optical pulse, and we have performed ‘cooling-by-measurement’ to reduce the mechanical mode temperature from an initial 1,100 to 16 K. Future improvements to this technique will allow for quantum squeezing of mechanical motion, even from room temperature, and reconstruction of non-classical states exhibiting negative phase-space quasi-probability.

Organisation(s)
Quantum Optics, Quantum Nanophysics and Quantum Information
Journal
Nature Communications
Volume
4
No. of pages
8
ISSN
2041-1723
DOI
https://doi.org/10.1038/ncomms3295
Publication date
08-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
103026 Quantum optics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/coolingbymeasurement-and-mechanical-state-tomography-via-pulsed-optomechanics(c29c90af-9e8f-4e2c-b197-97caa1a4d688).html