We aim to build instruments with world-class precision and performance that we can use to make measurements of high value and interest in both fundamental physics and more practical applications.
Many modern developments in today's society are based on high-quality clocks and oscillators: the Global Positioning System (GPS) satellite system, radar, optical fibre communications, even mobile phones. The group's goal is to develop new frequency standards and technologies with two endpoints in mind: to improve systems that are based on high-quality clocks and oscillators (such as those listed above), and to use these as precision tools to test the foundations of physics.
We are dedicated to commercialising our inventions and thus hold patents in conjunction with industry. Our research programs include strong international and industrial collaborations.
Our group undertakes research projects that cover a broad spectrum of interests, ranging from engineering to fundamental physics. Some of our projects include:
Main contact Professor Michael Tobar.
A ground based Yb lattice clock for participation in future space-clock missions.
Industry, defence and commerce all depend on accurate time keeping, and as clock technologies have improved they have unveiled capabilities such as the global positioning system (GPS) and very long baseline interferometry (VLBI). Atomic clocks have been at the forefront of physics for several decades and now they probe nature’s behaviour at the most fundamental level — in ways comparable in significance to high energy collider experiments, by searching for temporal changes in fundamental constants. Rather than rely on extraordinarily high energies, atomic spectroscopy relies on extraordinary levels of precision. The improvement in accuracy of clocks is advancing at approximately a factor of 500 per decade (compared to ~30 for Moore’s law). This rapid scientific advance suggests a certain inevitability with regard to finding new phenomena.
Recent measurements in various laboratories have shown astonishingly high accuracy for a number of different clock transition frequencies and ratios. These clocks are isolated in separate laboratories around the globe, thus the means to compare the clocks is heavily sought. With future space-clock missions such as the Atomic Clock Ensemble in Space (ACES) mission and possible future missions, such as Space Optical Clock (SOC) and STE-QuEST (Space-Time Explorer and Quantum Equivalence Principle Space Test), a much greater opportunity will be granted for frequency comparisons between clocks distributed around the earth.
At UWA we are developing an optical lattice clock based on a particular electronic transition in 171Yb, with the aim of participating in future space-clock missions. Such clocks have already demonstrated outstanding performance (e.g. at NIST, NMIJ, RIKEN & KRISS). The 171Yb ‘clock’ transition is included in the CIPM’s (Comité International des Poids et Mesures) list of secondary representations of the second.
Links to interviews with Dr McFerran about atomic clocks:
(The interview is about 10min in).
A candid discussion about atomic clocks
Contact: ARC Future Fellow John McFerran (08 6488 3481)
Many attempts to expand the Standard Model of particle physics via string theories or supersymmetry theories inevitably predict the existence of new particles that we have yet to observe. One such family of these hypothetical particles are the Weakly Interacting Slim Particles, or WISPs. As the name suggests, not only do WISPs interact very weakly with standard matter but they also have extremely small masses of less than 1 electronvolt. For comparison, a proton has a mass on the order of one billion electronvolts. What this means is that on an intrinsic level WISPs are remarkably difficult to detect and measure. It is these same properties that also allow WISPs to be formulated as compelling dark matter candidates.
The primary focus of our work is designing and performing experiments to search for a type of WISP known as the Hidden Sector Photon, or Paraphoton. This particle is coupled very weakly to the standard photon and does not interact with standard matter. We aim to constrain the strength of this photon / paraphoton coupling as a function of paraphoton mass.
One of our main experiments is known as a “Light Shining Through a Wall” experiment. Photons are generated on one side of an impenetrable barrier; in order to cross this partition the photon would need to convert to a paraphoton and pass through. By searching for photons on the other side of the barrier we can attempt to detect photon to paraphoton to photon conversion events. In order to reduce the level of background noise present in the detector the experiment is performed at cryogenic temperatures (approximately -270 C). As usual, we employ a variety of experimental tricks to enhance the sensitivity of our experiment and we are always applying the advances in measurement techniques we develop to other areas of research.
In addition to our work with Hidden Sector Photons we also collaborate with researchers at the University of Washington to try and improve the range and reach of their remarkable Axion Dark Matter eXperiment.
Contact: Stephen Parker