School Colloquia Series - Michael Tobar - High Precision Low Energy Measurements for Testing Fundamental Physics - 03 October
High Precision Low Energy Measurements for Testing Fundamental Physics
Prof. Michael Tobar
Frequency and Quantum Metrology Research Group and the ARC Centre of Excellence in Engineered Quantum Systems, School of Physics, The University of Western Australia.
This talk will discuss current and future precision experiments with phonons, photons and spins to test Lorentz Invariance and to Detect Dark Matter and High Frequency Gravitational Waves.
- We have currently undertaken some of the most precise tests of Lorentz invariance using photons  and phonons . High precision rotating experiments have been achieved with respect to the Standard Model Extension. These results will be presented along with our plans for the future.
- We present first results and future plans for the Oscillating Resonant Group AxioN (ORGAN) experiment, a microwave cavity axion haloscope situated in Perth, Western Australia designed to probe for high mass axions motivated by several theoretical models . The first stage focuses around 26.6 GHz in order to directly test a claimed result, which suggests axions exist at the corresponding mass of 110 µeV. Later stages will move to a wider scan range of 15-50 GHz (60 − 210 µeV). We present the results of the path finding run, which sets a limit on gaγγof 2.02 × 10−12 eV−1 at 26.531 GHz, or 110 µeV, in a span of 2.5 neV (shaped by the Lorentzian resonance) with 90% confidence. Furthermore, we outline the current design and future strategies to eventually attain the sensitivity to search for well-known axion models over the wider mass range. This includes new designs of tunable microwave cavities based on Bragg modes, with super mode tuning. We will also discuss plans to search for low mass axions below 10-6 eV . We are also undertaking experiments with YIG magnons, and currently have engineered resonant cavities with Ultra-strong and super-strong coupling . Such cavities can be used to search for axions through axion-spin interactions.
- Finally we will present our current work towards constructing macroscopic acoustic systems in their quantum ground state. Such systems are a priori sensitive to high frequency gravitational waves and can be used to test quantum mechanics [7-9].
 M Nagel, SR Parker, E Kovalchuck, PL Stanwix, J Hartnett, EN Ivanov, A Peters, ME Tobar “Direct Terrestrial Test of Lorentz Symmetry in Electrodynamics to 10-18,” Nature Comm., vol. 6, 8174, 2015.
 A Lo, P Haslinger, E Mizrachi, L Anderegg, H Müller, M Hohensee, M Goryachev, ME Tobar, “Acoustic Tests of Lorentz Symmetry Using Quartz Oscillators,” Phys. Rev. X, vol. 6, 011018, 2016.
 Ben T. McAllister, Graeme Flower, Justin Kruger, Eugene N. Ivanov, Maxim Goryachev, Jeremy Bourhill, Michael E. Tobar, arXiv:1706.00209 [physics.ins-det]
 Ben T. McAllister, Stephen R. Parker, and Michael E. Tobar, Phys. Rev. D 94, 042001 (2016)
 M Goryachev, WG Farr, DL Creedon, Y Fan, M Kostylev, ME Tobar, “High cooperativity cavity QED with Magnons at Microwave Frequencies,” Phys. Rev. Applied, vol. 2, 054002, 2014.
 N Kostylev, M Goryachev, ME Tobar, “Superstrong Coupling of a Microwave Cavity to YIG Magnons,” Appl. Phys. Lett., vol. 108, 062402, 2016.
 M Goryachev, ME Tobar, “Effects of geometry on quantum fluctuations of phonon-trapping acoustic cavities,” New J. Phys., vol. 16, 083007, 2014.
 M Goryachev, EN Ivanov, F van Kann, S Galliou, ME Tobar, “Observation of the Fundamental Nyquist Noise Limit in an Ultra-High Q-Factor Cryogenic Bulk Acoustic Wave Cavity,” Appl. Phys. Lett., vol. 105, 153505 2014.
 M Goryachev, ME Tobar, “Gravitational wave detection with high frequency phonon trapping acoustic cavities,” Phys. Rev. D., vol. 90, 102005, 2014.
Michael E. Tobar received the Ph.D. degree in physics from the University of Western Australia, Perth, W.A., Australia, in 1994. He is currently a Professor of Physics with the School of Physics at the University of Western Australia. Notably, between 2009 and 2014 He was awarded a Laureate Fellowship by the Australian Research Council.
His research interests encompass the broad discipline of frequency metrology, precision measurements and quantum, low temperature and condensed matter physics. He has co-authored about 260 journal publications in these fields of research and has 11 patents. Over his career he has used his expertise to undertake some of the best test of fundamental physics, and investigated many areas of physics using the developed precision and quantum measurement tools in his laboratory. He has also adapted such technology to the commercial sector. This includes the highly successful low noise room temperature and cryogenic sapphire oscillators as well as new sensor technologies developed within the ARC Centre of Excellence for Engineered Quantum Systems, which is funded until 2024. More recently he gained a contract to supply the National Institute of Measurement (NIM) in Beijing a Cryogenic Sapphire Oscillator for their atomic clock program. He is also the focal point of Australian participation in space experiments involving precision clocks and oscillators. Over his research career he has obtained approximately 25 Million AUD of funds directly for his research programs over his career and is a key CI for the ARC Centre of Excellence funded at 31 Million AUD over 7 years. Recent awards include the 2014 Cady Award presented by the IEEE, the 2014 Clunies-Ross award presented by the Australian Academy of Science and Technology, the 2012 Alan Walsh medal presented by the Australian Institute of Physics, the 2010 WA scientist of the year, presented by the WA dept. of Commerce, the 2009 Barry Inglis medal presented by the National Measurement Institute for precision measurement, the 2006 Boas medal presented by the Australian Institute of Physics. Also, during 2007 he was elevated to Fellow of the IEEE, 2008 the Australian Academy of Technological Sciences and Engineering and 2012 the Australian Academy of Science. He also received a citation from the Australian Learning and Teaching Council for inspiring research students to reach their full potential and transform to successful research scientists through participation in ground-breaking research. He was also recently elected as a voting administration committee (adcom) member for the IEEE Ultrasonics, Ferroelectrics and Frequency Control Society.