Using precision oscillators and interferometers to test fundamental physics

We present current work at the University of Western Australia to test fundamental physics using precision phase and frequency measurements. We describe two experiments under development. Firstly, we describe a continuously rotating cryogenic microwave oscillator constructed to test Local Lorentz Invariance (LLI). Initial results [1] improve limits set by previous non-rotating experiments [2, 3] by about an order of magnitude with only 3 months of data. Now, with over a year of data, we have reduced the noise floor by a factor of two. Secondly, we describe the development of a new, magnetically asymmetric, microwave interferometer with thermal noise limited readout, which will allow a sensitivity to the scalar and odd-parity coefficients for Lorentz violation in the photon sector of the Standard Model Extension of parts in 10(8) and 10(12) respectively.