A remarkable step toward next-generation energy-conservation

June 29, 2011 By Mikiko Tanifuji

Tohoku University, Osaka University and Japan Science and Technology Agency (JST) announced that they succeeded in directly observing electron spins in a topological insulator. The work has been published in Physical Review Letters with the lead author Seigo Souma, Assistant Professor of Tohoku University.

The charge of electron has been a basic carrier of information. However, another entity of electron, i.e. spin, is also expected to be an information carrier in the next generation systems. Topological insu-lator is a promising material recently recognized for the working spin, or a material for since its "edge" (e.g. surface on a ) serves as a conducting path depending on the spin pola-rization. Direct observation of spin states will be a key step to control electron spins in the material.

Researchers have performed spin-resolved photoemission spectroscopy of a topological insulator Bi2Te3 and present the first direct evidence for the existence of the out-of-plane spin component on the surface state. The magnitude of the out-of-plane spin polarization reaches maximally 25% of the in-plane counterpart. Its existence is presumed to come from the hexagonally deformed Fermi surface in momentum space, since no out-of-plane spin component is observed in another topological insulator TlBiSe2 with circular Fermi surface.

Although a problem remains in the quantitative difference from , researchers stated that the direct measurement of electron spins is a remarkable step toward a next-generation energy conservation device.

Explore further: CNST offers insights into metallic ferromagnetism using spin polarized electron probes

More information: S. Souma, et al, "Direct measurement of the out-of-plane spin texture in the Dirac-cone surface state of a topological insulator", Physical Review Letters, Vol. 21, No. 12, pp. 216803 (2011) [4 pages] Published May 25, 2011

Related Stories

Spin-polarized electrons on demand

January 15, 2009

Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Different from electronics, where whole ...

Electric control of aligned spins improves computer memory

January 19, 2010

Researchers from Helmholtz-Zentrum Berlin (HZB, Germany) and the French research facility CNRS, south of Paris, are using electric fields to manipulate the property of electrons known as "spin" to store data permanently. ...

New exotic material could revolutionize electronics

June 15, 2009

Move over, silicon -- it may be time to give the Valley a new name. Physicists at the Department of Energy's (DOE) SLAC National Accelerator Laboratory and Stanford University have confirmed the existence of a type of material ...

Spin-polarized electrons on demand

January 21, 2009

Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Different from electronics, where whole ...

Recommended for you

Electron highway inside crystal

December 8, 2016

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their ...

Researchers improve qubit lifetime for quantum computers

December 8, 2016

An international team of scientists has succeeded in making further improvements to the lifetime of superconducting quantum circuits. An important prerequisite for the realization of high-performance quantum computers is ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Vendicar_Decarian
not rated yet Jun 29, 2011
"next generation energy conservation device" ????

Claptrap.

No energy is carried via electron spin unless the electron is aligned with or anti-aligned with an external magnetic field, and even here the effect is weak.

The only application is spintronics, and while more efficient than silicon - precisely because spin energy is so small - that is the the only substantive energy conserving application.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.