2015 CAP Congress / Congrès de l'ACP 2015

Poor Q-factor? - no problem: nano-optomechanical mass sensing in ambient conditions

17 Jun 2015, 19:10

2m

CCIS Ground Floor PCL lounge (University of Alberta)

Poster (Student, In Competition) / Affiche (Étudiant(e), inscrit à la compétition) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) DCMMP Poster Session with beer / Session d'affiches, avec bière DPMCM

Speaker

Mr S. K. Roy (Department of Physics, University of Alberta and National Institute for Nanotechnology (NINT), Canada.)

Description

It has been demonstrated that optimum dynamic range (DR) and high quality factor (Q) of NEMS resonators provides unprecedented mass sensitivity [1]. The mass sensitivity and frequency stability of these devices are limited by their thermomechanical (TM) noise. TM noise goes down with Q as pressure increases, at the same time enhanced critical amplitude leads to a higher DR value with better sensitivity. However, detecting TM noise signal at ambient condition is always challenging. Optomechanical transduction successfully resolved this challenge with high displacement sensitivity and high bandwidth of NEMS devices [2]. Previously we have demonstrated the supremacy of our optical racetrack resonator transduction scheme in detecting TM noise signal [3]. Taking advantage of this measurement protocol we have found zeptogram level mass sensitivity at atmospheric pressure for a double clamped beam. This is similar to the sensitivity in high vacuum, even though Q-factor drops 300 fold from vacuum to ambient pressure. These intriguing experimental results challenge assumptions about fundamental limits of mass sensitivity of NOMS sensors and open the door for ultrasensitivity in ambient conditions. 1. K. L. Ekinci, Y. T. Tang and M.L. Roukes, “Ultimate limits to inertial mass sensing based upon nanoelectromechanical systems.”, J. Appl. Phys. Vol. 95. No.5, March 2004. 2. M. Li, W. H. P. Pernice, C. Xiong, T. Baehr-Jones, M. Hochberg, and H. X. Tang, “Harnessing optical forces in integrated photonic circuits.” Nature, Vol.456, pp.480-4, Nov.2008. 3. V. T. K. Saur, Z. Diao, M. R. Freeman, and W. K. Hiebert, “ Optical racetrack resonator transduction of nanomechanical cantilevers.” Nanotechnology, Vo.25, 05522, 2014.