A new two-dimensional topological insulator Successful formation of a bilayer bismuth
Topological insulators are a new state of matter which is increasingly attracting attention in condensed matter physics. While the bulk is an insulator, they have metallic edges (surface states) and these edge states have similar properties to magnets even though the bulk is not a magnet. There are hopes to develop novel devices utilizing this intriguing property.
In the present work, the research group led by assistant professor Dr. Toru Hirahara at the Department of Physics of the University of Tokyo’s Graduate School of Science has found a way to fabricate a new two-dimensional topological insulator. The remarkable thing about this material is that it is a bilayer ? composed of only two layers of bismuth atoms. While it is not impossible to make such a thin material (for example, the Nobel physics prize in 2010 was awarded to physicists who studied graphene, a single atomic layer of carbon), it still remains a major challenge. The present finding should accelerate research into the exotic properties of topological insulators as well as for their application in atomic-scale devices and quantum computation.
T. Hirahara, G. Bihlmayer, Y. Sakamoto, M. Yamada, H. Miyazaki, S. Kimura, S. Bl?gel, S. Hasegawa,
“Interfacing 2D and 3D topological insulators: Bi(111) bilayer on Bi2Te3,”
Physical Review Letters 107 (2011) 166801 doi: 10.1103/PhysRevLett.107.166801
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