Speaker
Paul Kim
(University of Alberta)
Description
Torsional resonators are an effective platform to study various material and optical properties. Current advances in nanofabrication techniques allow miniaturization of these torsional oscillators down to micron scale devices but they are often limited by their detection methods. Using a high quality optical resonator ($Q > 10^5$) coupled with a mechanical oscillator, which are the basis of cavity optomechanic, we can enhance torque and angular displacement sensitivities while significantly reducing the effective mass in the order of $\sim$ pg.
We have already demonstrated, for the first time, an optomechanical torsion device with torque sensitivities as low as 4 $\times$ 10$^{-20}$Nm/${\sqrt{\textrm{Hz}}}$ and angular sensitivity of 4 nrad/${\sqrt{\textrm{Hz}}}$. We are currently working on improving the design by maximizing the optomechanical coupling coefficient, $G$, which will be an important parameter in cryogenic temperatures where the thermally driven motion will be minimized at $\sim$ mK temperatures. We highlight our progress towards low temperature optomechanics with torsion paddles to improve the coupling rate in $\sim$ GHz/nm range. With our finest dilution refrigerator, upgraded to accommodate optomechanical systems, we hope to explore quantum regimes to study spin-mechanics coupled systems as well as mesoscopic properties of superconductors.
Author
Paul Kim
(University of Alberta)
Co-authors
Allison MacDonald
(University of Alberta)
Bradley Hauer
(University of Alberta)
Callum Doolin
(University of Alberta)
Hugh Ramp
(University of Alberta)
John Davis
(University of Alberta)
