23 Aug 2012

Physicists at Stanford University have confirmed the existence of a material that one day could lead to dramatically faster and more efficient computer chips.

New material allows electrons to travel on its surface with no loss of energy at room temperature. It can build circuits using conventional semiconductor technology. Such material can not only increase the productivity of modern electronic devices, but also become the cornerstone of a new type of computer industry – “Spintronics.”

Physicists Yulin Chen, Zhi Xun Shen and their colleagues tested the behavior of electrons in new bismuth telluride compound. The results were published online in the journal “Science Express” and clearly indicate that the material has the properties of topological insulator – a material that allows free flow of electrons to pass through the surface without energy loss.

The discovery was the result of teamwork between theoretical and experimental physicists at Stanford University. “The style of work at Stanford is perfect,” says Chen. “Theorists and experimenters always work together on a specific decision problem.”

Experimenters studied samples of the new compound, using X-rays, in the Stanford Radiation Laboratory and the National Laboratory – “Lawrence” at Berkeley. When Chen and his colleagues looked at the test results, they found that the material behaves even better than the theoretical models – bismuth telluride could tolerate even higher temperatures. This is possible thanks to a surprisingly good behavior of electrons. Quantum spin of each electron is aligned with the movement of electrons – called “quantum spin Hall effect.” This is one of the key properties used by Spintronics. “Hall effect means that electrons flow without resistance. When you run a current topological insulator, because this particular spin, the material is not heated, and the current flows without distractions, “says theorist Xiao Liang Qi.

Topological insulators can now be used in power transmission networks, as they can carry a small charge, but they can pave the way to new types of devices on a completely different basis.

Application in the real world of the new circuit will be relatively simple. Chen says, “Bismuth telluride is a three-dimensional material that is easy to manufacture with current semiconductor technologies. It is convenient to use. I think that the new material has a great future. “