Surface electron band structure of bismuth telluride. Credit: Yulin Chen and Z. X. Shen.
Researchers at the DOE’s SLAC National Accelerator Laboratory and Stanford University think they have a nifty new material that could unleash a new generation of spintronics applications, providing quicker and more efficient computer chips.
According to the SLAC and SU researchers, the material – a bismuth–telluride compound, Bi2Te3 – works as a topological insulator. The news release from the institution says, “[The new material] allows electrons on its surface to travel with no loss of energy at room temperatures and can be fabricated using existing semiconductor technologies. Such material could provide a leap in microchip speeds, and even become the bedrock of an entirely new kind of computing industry based on spintronics, the next evolution of electronics.”
The group published their findings recently in the online Science Express.
The discovery was set up by a great deal of theoretical work at the Stanford Institute for Materials & Energy Science, a SLAC-Stanford partnered project, followed by actually testing of a sample of the material at room temperatures.
Using X-rays from the Stanford Synchrotron Radiation Lightsource at SLAC and the Advanced Light Source, the group confirmed what the theorist predicted. Actually, the results exceeded expectations, showing the Bi2Te3 had a higher-than-predicted tolerance for temperature.
“This means that the material is closer to application than we thought,” said Yulin Chen, a physicist in the research group.
Another plus is that the material is not difficult to create or customize. “It’s a three-dimensional material, so it’s easy to fabricate with the current mature semiconductor technology. It’s also easy to dope—you can tune the properties relatively easily,” said Chen.
The investigators think their findings will accelerate the creation of devices with new operating principles. “When you hit something, there’s usually scattering, some possibility of bouncing back,” explained theorist Xiaoliang Qi. “But the quantum spin Hall effect means that you can’t reflect to exactly the reverse path . . . This could lead to new applications of spintronics, or using the electron spin to carry information. Whether or not it can build better wires, I’m optimistic it can lead to new devices, transistors, and spintronics devices.”