Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 2010 | Submitted + Supplemental Material
Journal Article Open

Back-action-evading measurements of nanomechanical motion


When carrying out ultrasensitive continuous measurements of position, one must ultimately confront the fundamental effects of detection back-action. Back-action forces set a lower bound on the uncertainty in the measured position, the 'standard quantum limit' (SQL). Recent measurements of nano- and micromechanical resonators are rapidly approaching this limit. Making measurements with sensitivities surpassing the SQL will require a new kind of approach: back-action-evading (BAE), quantum non-demolition measurement techniques. Here we realize a BAE measurement based on the parametric coupling between a nanomechanical and a microwave resonator. We demonstrate for the first time BAE detection of a single quadrature of motion with sensitivity four times the quantum zero-point motion of the mechanical resonator. We identify a limiting parametric instability inherent in BAE measurement, and describe how to improve the technique to surpass the SQL and permit the formation of squeezed states of motion.

Additional Information

© 2010 Macmillan Publishers Limited. Received 24 April 2009; accepted 10 November 2009; published online 6 December 2009. We would like to acknowledge helpful conversations with G. Milburn, M. Aspelmeyer, B. Plourde, M. Blencowe and R. Onofrio, and the assistance of P. Hauck, M. Corbett, S. Rosenthal and C. Macklin. The work has been supported by Cornell University and grants from FQXi and the National Science Foundation. A.A.C. wishes to thank the Canadian Institute for Advanced Research. Device fabrication was carried out at the NSF-sponsored Cornell Nanoscale Facility.

Attached Files

Submitted - 0906.0967.pdf

Supplemental Material - nphys1479-s1.pdf


Files (1.4 MB)
Name Size Download all
1.1 MB Preview Download
296.3 kB Preview Download

Additional details

August 19, 2023
October 20, 2023