*Note: This news was first mentioned in the June 2011 issue of Nanotech Japan Update*
Tohoku University, Osaka University and Japan Science and Technology Agency (JST) announced on May 17, 2011 that researchers of Tohoku University and Osaka University jointly succeeded in di-rectly observing electron spins in a topological insulator. The work has been supported by JST and 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 spintronics since its "edge" (e.g. surface on a bulk material) 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 theoretical prediction, researchers stated that the direct measurement of electron spins is a remarkable step toward a next-generation energy conservation device.
S. Souma, K. Kosaka, T. Sato, M. Komatsu, A. Takayama, T. Takahashi, M. Kriener, Kouji Segawa, and Yoichi Ando, "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
Mikiko Tanifuji | Research asia research news
Superconductivity research reveals potential new state of matter
17.08.2017 | DOE/Los Alamos National Laboratory
Spray-on electric rainbows: Making safer electrochromic inks
17.08.2017 | Georgia Institute of Technology
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy