M. Tobar - Precision low energy experiments to test fundamental physics and search for dark matter

At the University of Western Australia, the Frequency and Quantum Metrology research group within the Department of Physics has a rich history of developing precision tools for both fundamental physics and industrial applications. This includes the development of novel high-Q resonant photonic cavities such as whispering gallery modes and re-entrant cavities for example. These photonic cavities have been used in a range of applications, including highly stable low noise classical and atomic oscillators, low noise readout and measurement systems, high sensitivity displacement sensors, high precision electron spin resonance spectroscopy, high precision measurement of material properties and high-Q hybrid quantum systems strongly coupled to form quasi-particles.
The aforementioned technology has allowed the realization of precision measurement tools and techniques to test some of the core aspects of fundamental physics, such as searches for Lorentz invariance violations in the photon [1], phonon [2,3] and gravity sectors [4-6], variations in fundamental constants [7,8] and searching for ultra-light dark matter (ULDM) and weakly interacting sub-eV particle (WISP) dark matter[9-19]. We have also studied modified Maxwell’s equations and as a result have developed new experiments to test for Lorentz invariance violations, dark matter axions and hidden sector photons. We continue to follow this tradition and have recently gained funding to apply our expertise to new directions in fundamental physics with particular focus on detecting ULDMs and axions [9-19]. An overview of our current experiments, including status and future directions will be given. This includes experiments that take advantage of axion-photon coupling and axion-spin coupling to search for axion dark matter [9-19]. High acoustic Q phonon systems to search for high frequency gravity waves, scalar dark matter and tests of quantum gravity [20,21].

[1] M Nagel etal, Direct terrestrial test of Lorentz symmetry in electrodynamics to 10−18. Nature Comm., 6:8174 EP, 09 2015.

[2] A Lo etal, Acoustic Tests of Lorentz Symmetry Using Quartz Oscillators. Phys. Rev. X, 6, 011018, 2016.

[3] M Goryachev etal, Next Generation of Phonon Tests of Lorentz Invariance using Quartz BAW Resonators, IEEE Trans. UFFC, 65(6), pp. 991-1000, 2018.

[4] C-G Shao etal, Combined search for a lorentz-violating force in short-range gravity varying as the inverse sixth power of distance. Phys. Rev. Lett., 122:011102, Jan 2019.

[5] C-G Shao etal, Combined search for lorentz violation in short-range gravity. Phys. Rev. Lett., 117:071102, Aug 2016.

[6] C-G Shao etal, Search for lorentz invariance violation through tests of the gravitational inverse square law at short ranges. Phys. Rev. D, 91:102007, May 2015.

[7] M. E. Tobar etal, Testing local position and fundamental constant invariance due to periodic gravitational and boost using long-term comparison of the syrte atomic fountains and h-masers. Phys. Rev. D, 87:122004, Jun 2013.

[8] J Guena etal, Improved tests of local position invariance using 87Rb and 133Cs fountains. Phys. Rev. Lett., 109:080801, Aug 2012.

[9] BT McAllister etal, Axion dark matter coupling to resonant photons via magnetic field. Phys. Rev. Lett., vol. 116, 161804, 2016.

[10] BT McAllister, SR Parker, ME Tobar, 3D lumped LC resonators as low mass axion haloscopes. Phys. Rev. D 94, 042001, 2016.

[11] BT McAllister etal, The ORGAN experiment: An axion haloscope above 15 GHz. Physics of the Dark Universe, 18, 67–72, 2017.

[12] M Goryachev etal, Axion detection with negatively coupled cavity arrays. Phys. Lett. A, vol. 382, pp 2199–2204, 2018.

[13] BT McAllister etal, Tunable Super-Mode Dielectric Resonators for Axion Haloscopes. Phys. Rev. Applied, vol. 9, 014028, 2018.

[14] M Goryachev etal, Probing Dark Universe with Exceptional Points. Physics of the Dark Universe, vol. 23, 100244, 2019.

[15] B McAllister etal, Cross-correlation Signal Processing for Axion and WISP Dark Matter Searches. IEEE T-UFFC, 66(1) 236-43, 2019.

[16] G Flower etal, Broadening Frequency Range of a Ferromagnetic Axion Haloscope with Strongly Coupled Cavity-Magnon Polaritons. Physics of the Dark Universe, vol. 25, 100306, 2019.

[17] ME Tobar etal, Modified Axion Electrodynamics as Impressed Electromagnetic Sources Through Oscillating Background Polarization and Magnetization. Physics of the Dark Universe, vol. 26, 100339, 2019.

[18] M Goryachev etal, Axion Detection with Precision Frequency Metrology. Physics of the Dark Universe, vol. 26, 100345, 2019.

[19] G Flower etal, Experimental implementations of cavity-magnon systems: from ultra-strong coupling to applications in precision measurement. New J. Phys., vol. 21, 095004, 2019.

[20] M Goryachev, ME. Tobar, Gravitational wave detection with high frequency phonon trapping acoustic cavities. Phys. Rev. D, 90(10), 102005, 2014.

[21] PA Bushev etal, Testing the generalized uncertainty principle with macroscopic mechanical oscillators and pendulums, accepted to be published in Phys. Rev. D, 2019.


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