Electron spins in a topological insulator was observed for the first time

Researchers from Japan have succeeded in directly observing electron spins in a topological insulator (Bi2Te3). Topological insulator is a promising material for Spintronics because its "edge" can serve as a conducting path depending on the spin polarization.

The magnitude of the out-of-plane spin polarization is 25% at most compared to the in-plane counterpart. The researchers say that the out-of-plane spin polarization exists because of the hexagonally deformed Fermi surface in the Bi2Te3, because it does not exist in TlBiSe2 which has a circular Fermi surface.

Heusler compounds can behave like topological insulators, can be used for spintronics devices

Teams from the Johannes Gutenberg University Mainz (JGU) in Germany and Stanford University have uncovered a new quantum state of matter in Heusler compounds which they claim opens up 'previously unimagined usage possibilities'. The scientist from Mainz has shown that many Heusler compounds can behave like topological insulators (TI).

TIs have been studied in the field of solid state and material physics. Characteristic of topological insulators is the fact that the materials are actually insulators or semiconductors, although their surfaces or interfaces are made from metal - but not ordinary metal. Like superconductors, the electrons on the surfaces or interfaces do not interact with their environment - they are in a new quantum state. In contrast with superconductors, topological insulators have two non-interacting currents, one for each spin direction. These two spin currents, which are not affected by defects or impurities in the material, can be employed in the futuristic electronics field of 'spintronics' and for processing information in quantum computers.