The Research School of Physical Sciences and Engineering is part of the IAS (Institute of Advanced Studies) at the ANU (Australian National University). The Research School contains about 300 Scientists, Support Staff and Postgraduate Students. We also have a number of Undergraduate Students who have chosen to either work as vacation Scholars or who are working on their Honours projects within the School. If you are interested in knowing a little more about working as a student within the School, you may like to visit http://rsphysse.anu.edu.au/admin/School_Pages/prospect_student.html
What type of research do we do at the School?
As our name suggests, we are interested in Physics and Engineering. These are rather vast fields, so we have to concentrate our efforts in specific areas. The School is divided into eight such areas, or Departments.
Plasma Physics
There are four states of matter, solid, liquid, gas and plasma. Plasmas are extremely hot. So hot in fact that the atoms within them break down into separate electrons and ions. Under the right conditions it is possible to induce Nuclear Fusion within plasmas. Fusion is the process which powers the sun, and one day might provide an abundant and clean source of power on earth. (Unlike current Fission power stations, a fusion reactor produces no long lived radioactive or toxic wastes, nor is there the danger of meltdowns). A major difficulty with harnessing this power, is making a vessel that can hold such a hot substance without melting. Scientists overcome this by using magnetic bottles. These are very strong magnetic fields which repel the plasma from the metal outer wall of the container. The School houses one of Australia's largest plasma confinement devices, the H1-NF.
Plasmas are also used in the processing of semiconductors where they offer substantial advantages over conventional chemical techniques
Nuclear Physics
Within the Department of Nuclear Physics, we study the behaviour and interaction of the nuclei of atoms. Our focus is on gaining an understanding of the true nature of matter, rather than nuclear devices such as reactors and bombs. The nucleus of an atom is only 0.00000000001mm across, far too small to see even with an electron microscope (the most powerful microscope yet invented). So scientists study these tiny objects by smashing them together in machines called accelerators. Occasionally two nuclei collide and react. The energy and direction of the particles that "fly out" during these collisions, give valuable information about the nature of the nuclei involved. Using complex calculations, scientists can then begin to build up a picture of the many types of atomic nuclei that exist in nature.
Understanding the true nature of atomic nuclei is vital in piecing together a complete picture of the world around us. Once the contribution science made to the world could perhaps be seen as a series of separate inventions, such as electric motors and clocks. However, modern science has become so complex that a complete understanding of the nature of matter is required in order to progress towards higher technology. Both electronics and lasers were "born" of what seemed at the time, rather abstract research.
Electronic Materials Engineering
Within Electronic Materials Engineering we study semiconductor materials of technological importance. We use accelerators, similar to the ones in Nuclear Physics, to learn more about the nature of such materials. As we gain knowledge in this area, we can make better and better devices. Basic research such as this is the reason we are able to build ever faster and more powerful computers.
Electronic Materials Engineering also houses one of Australia's best MOCVD semiconductor growth facilities. This machine is able to grow semiconductor wafers with layers of different materials only a few atoms thick. Such wafers are the building blocks of the tiny semiconductor lasers contained in CD players and optical telecommunications networks. Such technology is expanding at an exponential rate, and it is vital that Australia has an active role in the design and manufacture of such devices.
Laser Physics Centre
LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. Stimulated emission is where an atom has a surplus of energy and releases this energy as a packet of light when stimulated to do so by another packet of light. One of the interesting, and useful, properties of such emission is that the two packets are identical. Thus by passing light many times through the same medium, it is possible to get amplification and produce very intense beams of identical packets of light - coherent light. This is what gives laser light its "speckley" look and why lasers are so directional.
Scientists at the Laser Physics Centre use lasers to modify and study technologically useful materials. It is possible to discover a lot of things about the structure and composition of matter by studying how it absorbs or emits different wavelengths of laser light.
Certain materials have what are know as non linear optical properties. Put simply, this means that unlike glass, how much they bend light, depends on how bright the light is. Using these non linear materials, it is possible to turn red laser light into blue or ultraviolet light.
Optical Sciences Centre
Scientists at the Optical Sciences Centre study the behaviour of laser light in narrow confining channels known as wave guides. If a guide or "pipe" is small enough, it does more than channel the light in a particular direction. It determines the type of light which can propagate down it. Another surprising fact about light in waveguides is that some of the light propagates beyond the walls of the guide - so called evanescent waves. This means that it is possible to take light in or out of such a light pipe without making a hole in the wall. Using these properties of waveguides scientists are able to make devices such as optical switches which may form the basis of super fast optical computers of the future.
One of the most exciting aspects of this work is that by using non-linear materials it is possible to make the laser actually write the waveguide in the material it is travelling through. In this way one laser is able to steer a path for another.
Atomic & Molecular Physics Laboratories
Scientists in the Atomic & Molecular Physics Laboratories study atoms and molecules in a similar way to that in which nuclear physicists study the nuclei of atoms. All of the matter around is composed of atoms and the behaviour of these atoms towards each other is what gives different materials their properties. It's why water's wet and sand isn't, or rock's hard and skin's soft. One area of particular interest to the scientists here is the microscopic manipulation of individual atoms. Using lasers and magnetic fields, they have been able to hold and manipulate single atoms, rather like a fantastically small pair of tweezers. Having such control over individual atoms has also allowed them to produce very stable and accurate atomic beams (streams of atoms). Such atomic beams show considerable promise for lithography, which is the writing of very fine patterns on materials. Lithography is the process by which all computer chips are made. With current light based technology, there is a limit to the size of the features one can produce, and correspondingly a limit to the power of the devices one can make. It is possible that atomic beam lithography may change all of this.
Applied Mathematics
Much of the work within Applied Mathematics is devoted to surfaces. The surface of objects is a very interesting place. It is the surface we interact with when we pick something up, or paint it, or taste it. A sticky sweet is sticky because of its surface properties. Scientists within Applied Mathematics study surfaces in a number of ways.
Our study of surfaces has lead to the design of highly innovative scientific instruments such as the Surface Forces Apparatus (SFA). The SFA is a machine designed to measure the incredibly small forces between surfaces. Researchers also use atomic force microscopy to examine surfaces. An atomic Force Microscope is rather like a Braille version of a normal microscope, instead of seeing the surface it drags a tiny finger across it and "feels" the lumps and bumps.
Scientists need to make accurate mathematical models of surfaces in order to match theoretical predictions to experimental results. However, some surfaces, such as the interior of coral shells and termite nests are incredibly complex and it is extremely difficult to describe them using conventional geometry. Our researchers have adopted a novel approach to this problem using non-Euclidean geometry (a strange mathematical world where shapes that are impossible in the physical world, can exist) Using this non-Euclidean Geometry, they are able to make more accurate models of these complex surfaces.
Theoretical Physics
One of the great strengths of science it its dual approach to problem solving - experiment and theory. Without experiments it is impossible to know if theories are correct and without theory is very hard to know which experiments to do. Researchers in the Department of Theoretical Physics work on complex mathematical and computer models of nature. Some of this work provides theoretical support for the experimental workers within the School. For example, because of the enormous cost of plasma containment systems, it is vital to have accurate mathematical models of such systems to aid design. When you've just spent ten million dollars on a confinement vessel, you really don't want to find out that it would have been better if it was 20cm bigger or round rather than square!
Why do we do research?
Good science is expensive. Very expensive. Do we need it in these difficult times?
To make an intelligent judgement about the value of science one has to look at the big picture. All the technology that gives us computers, aircraft, electricity, medicine and our comfortable and interesting modern life style comes from science. It comes from discoveries that at the time may have seemed obscure and irrelevant. When you break your leg and doctors are able to use x-rays to asses the damage, or you watch your favourite TV program, or listen to a CD you are using technology solely based on such discoveries. The problem with modern science is that the time from cutting edge discovery to useful product is very long, often ten or twenty years. So it can seem that you get nothing for your money, but in reality, you get the entire modern world for your money. If Australia stops investing in Science, the rest of the world will not and we will be left behind. That means that instead of Australian workers making high tech products, we will be forced to buy more and more from overseas that's bad for all of us!