A research team from UOW’s Institute for Superconducting and Electronic Materials (ISEM) and the Faculty of Engineering’s Australian Institute for Innovative Materials has undertaken breakthrough research into a new class of materials called topological insulators.


Spintronic and Electronic Materials team leader Professor Xiaolin Wang said that topological insulators are a new class of materials that conduct electric current and do not conduct electric current simultaneously. Their inside is insulating while their outside/ surface is conduscting, allowing the material to become a ‘metallic insulator’.


Professor Wang said such a type of material has many fascinating physical and chemical properties.


The team has also made a breakthrough in the observation of significant change of resistance with application of magnetic field in such kind of topological insulator nano-sheet at room temperature. The observation paves the way for the topological insulators to be useful for practical applications in magnetoelectronic sensors, spin electronic devices such as disk reading heads, mechatronics, and other multifunctional devices.


This work led by Professor Xiaolin Wang, and co-authored by Dr. Yi DU, Professor Shixue Dou and Professor Chao Zhang has been published in Physical Review Letters.


According to Professor Wang, the topological insulator is a special case of a new class of materials that was invented and published in Physical Review Letters by Professor Wang in 2008, and reviewed in a Review article in Nature Publishing Group, Asia Materials in 2010 by Professor Xiaolin Wang, Professor Shixue Dou and Professor Chao Zhang.


In collaboration with teams from Netherland Institute for Nanotechnology, University of Twente High Field Magnet Laboratory Institute for Molecules and Materials, Radboud University Nijmegen and Leiden Institute of Physics, Leiden University, another breakthrough was made for the composite of a topological insulator and a superconductor early this year.


The joint team discovered that supercurrent in a superconductor can pass through a thin layer of topological insulator without losing superconductivity. The realisation of supercurrents through topological metallic surface states is an important step towards the detection of the elusive Majorna particle which is its own antiparticle.


The joint work has been published in Nature Materials, Jan 2012.


Professor Wang said the team’s latest developments on this new class of materials was showcased t the 4th International Conference on Spintronics held in Sydney last week.


The Director of ISEM, Professors Shixue Dou said research on the new class of materials has boosted the reputation of ISEM’s world-class capability in materials design and fabrication. This capability is extremely important in research of advance materials and condensed matter physics.


The researchers acknowledged the support they received via funding from the Australian Research Council through Discovery projects.