What's On at UWA

I will try to describe what nonlinear sigma-models are and how they allow the study of geometry. After explaining some physical motivations for the study of these models, I will review actions and symmetries (including supersymmetry) and symmetry algebras. On the math side, I will review Riemannian, Kahler, and hyperkahler geometry, and discuss quotients in all three contexts.

Seminar organisers: Professor Sergei Kuzenko, Physics; Winthrop Professor Cheryl Praeger, Mathematics

Magnetic domain patterns form in perpendicularly-magnetized ultrathin films due to the combination of short-range attractive magnetic exchange interactions and long-range repulsive magnetic dipolar interactions. The dynamics of these patterns, and the domains within them, are described by the complicated interplay of different relaxation processes that act across many orders of magnitude in temporal and spatial length. Our recent measurements of Fe/ 2 ML Ni/W(110) films have permitted the quantitative separation and characterization of these times scales through measurements of the ac magnetic susceptibility. The processes include the motion of existing domain walls, the creation and annihilation of domain walls, and the transformation between domain wall patterns. The temporal analysis of this hierarchy complements an extensive literature that uses microscopy to characterize the domains spatially.

When quantitative, usually nonlinear, models of observed phenomena are developed they are typically incomplete as many unknown parameters remain. Further to use the model to forecast future behaviour, one must accurately estimate the full state of the system when predictions begin and measurements are usually only of a subset of the variables describing the system state.

We describe and illustrate tools for the exact description of transferring information from such sparse measurements to quantitative models when the observations are noisy, the model has errors, and there is uncertainty in the state of the system when observations begin. While the discussion is quite general, the ideas are illustrated by examples selected from neurobiology and geophysics. The important role of nonlinearity in the procedure is emphasized.

Over many years of dynamic and energetic development, quantum chemistry turned into a fully mature science able to describe and model molecular systems containing even hundreds of atoms. Its capabilities are continuously growing along with the progress in computer miniaturisation and the development of faster and parallel computational algorithms. In our quest to unravel molecular mysteries deeply rooted in the NANO&BIO world, with most funding grants scaling super-linearly with the size of studied atomic systems, and with the constantly growing complexity of the modern research techniques, we seldom take a moment to look back at the roots of quantum chemistry, at the underlying approximations, and the resulting issue of the error control. This seminar is supposed to show you how surprising such a look can be.

Current condensed-matter research strives for ever declining system sizes and faster probing techniques. This goes with the impressive capability of the controlled synthesis of materials allowing for new functionalities such as the control of magnetism with electric fields and vice versa. The appropriate theoretical models should thus be capable to capturing quantum and mesoscopic effects as well as the case of coupled order parameters such as field-driven multiferroics. In this talk I will summarize our studies of the field-driven, spin-dependent dynamics in nanostructures and how this dynamics can be accessed experimentally [1,2]. The transition to the classical treatment is then addressed as well as the question of how to optimally control the magnetization dynamics in metallic nanomagnets [3]. A further issue is how the polarization evolves for a ferroelectric oxide driven by an electric field and how to capture the coupled magnetization/polarization dynamics in multiferroic nanostructure in the presence of time-dependent electric and magnetic fields [4].

[1] A. Matos-Abiague, J. Berakdar, Phys. Rev. Lett. 94, 166801 (2005). [2] Y. Pavlyukh, J. Berakdar, Chem. Phys. Lett. 468, 313 (2009). [3] A. Sukhov, J. Berakdar, Phys. Rev. Lett. 102, 057204 (2009). [4] A. Sukhov, C. L. Jia, P. P. Horley and J. Berakdar, J. Phys.: Condens. Matter 22, 352201 (2010).

We are inviting all undergraduate, post graduate, and recent graduates, from Physics, Maths, atmospheric science and Ocean & Climate Science disciplines to come and find out about the exciting career opportunities available with the Australian Bureau of Meteorology.

There is something so immediately special about light that makes it fascinating. My daily exploitation of the weird properties of light emphasises its intrinsic strangeness and usefulness. This talk is intended to discuss and demonstrate some of these strange behaviours and to introduce you to some of the exciting and unexpected applications of the most pure form of light: the laser. Examples include the use of lasers in medicine, making the world’s best clocks, cooling matter to incredibly low temperatures, making the most precise measurements ever made and scrutinising whether Einstein’s predictions about the Universe are really correct.

Andre Luiten is a Professor of Physics at the University of Western Australia. He runs a research group aimed at using lasers to make precision measurements for both industry and for academic purposes. He was the joint inaugural winner of the Premier’s Prize for Early Career Achievement in Science.

Illuminating Lectures

This Illuminating Lecture is the first in a series of public lectures in which local scientists will provide insight into some of the fascinating research being conducted in the field of light. The lecture series coincides with Scitech’s current feature exhibition Playing with Light. For more information visit the Scitech website.

Scitech’s Playing with Light exhibition will be open before and after lecture. Doors open 6.00pm, lecture 6.30-7.30pm.

Cost: $5 per person, free for Scitrekkers. Tickets will be available at the door but pre-booking is highly recommended.

The rail industry is a vital and challenging industry which can offer careers to students of Engineering; Project management; Business/Commerce; Safety, Risk, OHS & Human Factors; Information technology; and spatial sciences.

The Railways Technical Society of Australasia (RTSA) is holding its inaugural Meet the Railway People Expo, for degree and diploma undergraduate students (from years 1 to 4) from Western Australian tertiary institutions.

The Meet the Railway People Expo will bring together undergraduate students from WA tertiary institutions and industry - to highlight the diversity of occupationns and the challenging careers within the rail industry and to build understanding of the industry.

The Meet the Railway People Expo is a half day event from 9:30am to 2pm on Saturday 7 May at the Rydges Hotel Perth, corner of Hay and King Streets. Entry is by the marked lift right on the building corner. Registration is FREE for students - www.engineersaustralia.org.au/waexpo.

If you require further information on the Railways Technical Society of Australasia (RTSA) - Please check website www.rtsa.com.au.

If you wish to attend, you must register for event management purposes at www.engineersaustralia.org.au/waexpo.

FURTHER DETAILS ON CAREERHUB - https://uwa.careerhub.com.au

The word educate is derived from educare (Latin), meaning to draw out, to bring out potential. Educational systems, the world over, are based on thrusting knowledge onto students, instead of drawing it out of them. As a result, students become well informed on one or more subjects. Such education renders a student intelligent, but when it comes to handling life’s challenges and making the right choices, mere intelligence will not guarantee the best result. This fact is exemplified by the problems of obesity, addictions, stress and depression among highly intelligent people. These talks, held over two nights, will investigate how we can solve many of life’s problems by simply understanding and implementing the value of education, which is to build and strengthen one’s inner personality. When an individual’s character is developed, he or she becomes well equipped to make responsible choices and face life’s challenges with ease.

Western Australia could soon be home to the biggest international science investment in Australia’s history. This would arrive in the form of a new Advanced Gravitational Wave Observatory, valued at about $300 Million. The observatory would combine the most precise mirrors and the largest vacuum ever created, and laser beams that might blow up the death star! The observatory, called LIGO-Australia is planned to be installed near Gingin, one hour’s drive north of Perth. LIGO-Australia will be the most sensitive measuring instrument ever created, able to measure gravitational “sounds” from black holes and the birth of the universe. The sounds, which in reality are ripples in space and time, are a billion times softer than the softest sound detectable by the human ear. The Gravitational Observatory offers an exciting opportunity for Australian industry. Vacuum pipe construction and innovative geothermal cooling technology will provide WA companies with an advantage in international markets. Some of the most sophisticated digital control systems ever created will boost industrial control technology. Data analysis will use teraflop graphics processors, which are being developed in collaboration with the Square Kilometer Array (SKA) radio telescope project. Refreshments will be available after the talk. Ms Alannah MacTiernan will introduce the Speaker. Ms MacTiernan was MLA representing Armadale from 1996 to 2010, and Minister for Planning and Infrastructure overseeing a number of major rail and road infrastructure projects. She has had a long interest in science

I will be talking about the NPL's efforts and outlook for the next few years in determining the Boltzmann constant (k) with ~1 part-per-million uncertainty using a resonant acoustic method. This may be of particular interest to some people in Physics as there is currently a measurement of k in progress in the basement performed using a completely different method. Prof. Machin will also be talking about developments in thermometry at high temperatures (>1000 C) using thermocouples and self-validating techniques for extreme environments.

Magnetic thin films with their magnetic moments spontaneously aligned perpendicular to the film plane are of great interest for their practical applications. This configuration is applied in perpendicular recording media with increased data storage density. New materials with a larger tendency to align perpendicular to the plane (i.e. with larger perpendicular anisotropy) could further increase the storage density.

One way to induce perpendicular anisotropy is by distorting the lattice of single crystalline films. In cubic lattices the distortion along the c axis lowers the symmetry causing an increased orbital moment and the spin-orbit coupling forces the moment to align perpendicular to the film plane. A large perpendicular anisotropy in tetragonally distorted Fe100-xCox alloys was theoretically predicted for bulk materials [1]. Experimentally this was achieved by growing thin films on substrates with mismatched lattice parameters such as Rh and Ir(001) [2]. The interface between the substrate and the film can significantly influence the magnetic behaviour but was not considered in the theoretical prediction. Furthermore the distortion can be expected to relax as the film is made thicker and approaches bulk-like behaviour but the mechanism of this relaxation remains unclear.

The Fe100-xCox /Ir(001) system has been studied in an attempt to understand the correlation between film structure, nature of the interface and structural relaxation to the magnetic properties. An onset of ferromagnetic ordering and the increase and decay of the perpendicular anisotropy with the composition and thickness were observed. Comparison between the magnetic behaviour of Fe100-xCox on Ir and Rh(001) surfaces highlight the peculiar properties of the Ir(001) surface and may shed light on the mechanism for inducing perpendicular anisotropy by tetragonal distortion.

[1] T. Burkert et al., Phys. Rev. Lett. 93, 027203 (2004). [2] F. Yildiz et al., J. Appl. Phys. 105, 07E129 (2009).

The 10 most engaging 3 Minute Thesis presenters selected at the UWA semi-finals on 21st July, will compete for prizes and the opportunity to represent UWA at the Australia-New Zealand 3MT competition in September. Please come along to support the presenters and vote for your "People's Choice".

Presentations over this two-day event will cover comparisons of environments for the dawn of life on Earth and comparing with the possibility of life on the red Planet, Mars.

Written submissions from teachers, scientists, engineers, social theorists, managers, writers and artists are welcomed. Full papers will be reviewed and published in accordance with the DEEWR guidelines.

Topics include (but are not limited to):

Mars - Earth analogue comparisons, strategies and technologies for surface exploration, field science for exploration, recruiting the next generation of explorers, astronauts, scientists and engineers, educational needs for a spacefaring culture, the Mars Society as a culture, new concepts in project management, remote-area engineering, Mars as an inspiration to science students and artists.

The De Laeter Youth Lecture is organized annually by the WA Branch of the Australian Institute of Physics. It is named in honour of the late Emeritus Professor John De Laeter. Not only was Professor De Laeter one of Western Australia's most noted scientists, but he also had an enormous impact on education is Western Australia. A minor planet was named after Professor De Laeter in recognition of his research in astrophysics and, in 1992, he was awarded the Officer of the Order of Australia (AO) for his contributions to science, education and industry. He received a Eureka Prize in 2005, and a Clunies Ross Science and Technology Award in 2006.

A new perspective on renormalization is taken by use of an iterative wavelet based averaging as suggested by Stephane Mallat. This replaces the band limited Fourier transforms used currently. The result is a hierarchy of fundamental excitations of the system based on the complexity of the interaction (the number of scales) and the size of the interactions (the scale sizes). The system can then be second quantised with the state of the system given by occupation numbers or the number of each of the fundamental excitations of the system. This gives a natural metric for the state of the system (in terms of these occupation numbers), and a complete specification of the dynamics by the renormalized action (which is diagonal) in this renormalized coordinate system. It should be noted that the wavelet based averaging needs to respect the group symmetries of the dynamics. This method also has application to the understanding of complex systems, as it gives a metric for complexity; and has application to the identification of image texture.

BIO: Michael E. Glinsky received a B.S. degree in physics from Case Western Reserve University in 1983 and a Ph.D. degree in physics from the University of California, San Diego in 1991. His doctoral research on magnetized pure electron plasmas was recognized by the American Physical Society as the outstanding thesis in the United States (1993 Simon Ramo Award). Before enrolling in graduate school as a National Science Foundation Graduate Fellow, he worked as a geophysicist for Shell Oil Company. After graduate school, he worked as a Department of Energy Distinguished Postdoctoral Research Fellow at Lawrence Livermore National Laboratory for 5 years. More recently he worked for three years at the Shell E&P Technology Co. doing research on Bayesian AVO and 4D inversion. After being the Section Leader of Quantitative Interpretation for BHP Billiton Petroleum, he moved into the BHP Billiton corporate centre where he was Manager, Resource R&D. Currently, he is CEO Science Leader at CSIRO, and an Adjunct Professor of Physics at University of Western Australia. He has published over 25 papers in the refereed scientific literature on subjects as varied as plasma physics, signal processing for oil exploration, x-ray diagnostics, application of exterior calculus to theoretical mechanics, and laser biological tissue interactions. He received the 2004 CSIRO Medal for Research Achievement for his research on petroleum reservoir characterization.

UWA opens up the whole campus to the public.

Come and find out about the courses on offer, valuable research, community programs, and facilities...all mixed with a day full of lots of fun activities for everyone!

Over the next decade or so, extremely large, ground-based telescopes will be built to probe the furthest reaches of the universe - back to the earliest times in its evolution, and through its most energetic events. These instruments will span the optical and radio bands of the electromagnetic spectrum and the audio band of the gravitational wave spectrum. WA is on the verge of hosting two of these three telescopes – the Square Kilometre Array radio telescope and the LIGO-Australia gravitational wave telescope. In this talk we will explain how a gravitational wave telescope works and illuminate the exciting physics, astrophysics and cosmology that can be done with a global array of such telescopes.

Professor McClelland, a former graduate of the University of Western Australia, is currently Head of the Department of Quantum Science and Director of the Centre for Gravitational Physics at The Australian National University.

Professor Blair is Director of the Australian International Gravitational Research Centre at the University of Western Australia.

To register please visit https://www.eventbrite.com/event/1808452129

Over the next decade or so, extremely large, ground-based telescopes will be built to probe the furthest reaches of the universe - back to the earliest times in its evolution, and through its most energetic events. These instruments will span the optical and radio bands of the electromagnetic spectrum and the audio band of the gravitational wave spectrum. WA is on the verge of hosting two of these three telescopes - the Square Kilometre Array radio telescope and the LIGO-Australia gravitational wave telescope.

Interested in working for the Australian government intelligence agencies? Come along and find out more!

Australian citizens in all disciplines.