UZH physicist is researching a new class of material, the so-called topological isolators in higher order. The edges of these crystalline solids lead to powerlessness while the remainder of the crystal is isolated. This would be very useful in semiconductor technology and in the construction of quantum computers.
Topology examines the properties of objects and solids that are protected against disturbances and deformation. Known so far are so-called topological insulators – crystals that are electrically insulating in the interior, but outdoors lead electricity. The leading states of state are topologically protected and are difficult to transform into isolating states.
New Material Class "Higher Order Topological Insulators"
Theoretical physicists led by Zurich University have now investigated a new class of topological insulators not on the surfaces, but on the crystal edges have leading states. The team of researchers from UZH, Princeton University, the Donostia International Physics Center and the Max Planck Institute for Microstructure Physics in Halle have renamed this new class of material "top order insulators of higher order". These are particularly interesting because the electrically conductive edges are extremely robust: impurities or disturbances in the crystal do not stop the flow of topologic electrons, the current just flows around the obstacle.
Edges are like electrons for a highway  Edges need not be specially prepared to be leading. If the crystal breaks, the new edges are also automatically conductive again. "The most exciting thing is that electricity can be carried out in this way, at least theoretically without resistance," says Titus Neupert, professor at the Institute of Physics at UZH. "One can imagine the edges of the crystal as a motorway for electrons, they can not just turn back." This property of resistance-free conductivity, which is known above all for superconductors at low temperatures, can not be found in the prior art topological insulators with conductive surfaces.
Further theoretical and experimental studies are necessary
Theoretical aspects still dominate in the study of physicists. As the first association to have these new properties, they have suggested sparkling time. "We need to identify additional possible materials in this new class and to investigate them in experiments," says Neupert. The researchers hope that nanotreads, which consist of the higher order topological insulators they study, can be used in the future as interconnections in electrical circuits. They can be combined with magnetic and superconductive materials and used in quantum computers.