Nov 19 2020
A semiconductor has been successfully transformed into a superconductor by three physicists from the Department of Physics and Astronomy at the University of Tennessee, Knoxville, and their collaborators from the Southern University of Science and Technology and Sun Yat-sen University in China.
Hanno Weitering. Image Credit: University of Tennessee Knoxville.
The team that achieved the advancement in fundamental research includes Professor and Department Head Hanno Weitering, Associate Professor Steve Johnston, and Ph.D. Candidate Tyler Smith. The discovery could result in unexpected developments in technology.
Although semiconductors are electrical insulators, they conduct electricity under unique conditions. They are the main components in several electronic circuits found in day-to-day items such as computers, televisions, digital cameras, and mobile phones.
With the advancement in technology, the development of semiconductors has also advanced, enabling the fabrication of electronic devices that are faster, smaller, and more reliable.
Discovered first in 1911, superconductors allow electrical charges to travel without resistance, enabling current to flow without any energy dissipation. Researchers are still looking for practical applications of superconductors, but at present, they are mainly used in MRI machines.
Weitering and his collaborators used a silicon semiconductor platform—the standard for almost every electronic device—to make the superconductor.
When you have a superconductor and you integrate it with a semiconductor, there are also new types of electronic devices that you can make.
Hanno Weitering, Professor and Department Head, University of Tennessee at Knoxville
Superconductors were actually discovered accidentally; the advent of this novel superconductor is the first instance of purposely making an atomically thin superconductor on a traditional semiconductor template, leveraging the know-how of high-temperature superconductivity in doped “Mott insulating” copper oxide materials.
The entire approach—doping a Mott insulator, the tin on silicon—was a deliberate strategy. Then came proving we’re seeing the properties of a doped Mott insulator as opposed to anything else and ruling out other interpretations. The next logical step was demonstrating superconductivity, and lo and behold, it worked.
Hanno Weitering, Professor and Department Head, University of Tennessee at Knoxville
Weitering added, “Discovery of new knowledge is a core mission of UT. Although we don’t have an immediate application for our superconductor, we have established a proof of principle, which may lead to future practical applications.”
Journal Reference:
Wu, X., et al. (2020) Superconductivity in a Hole-Doped Mott-Insulating Triangular Adatom Layer on a Silicon Surface. Physical Review Letters. doi.org/10.1103/PhysRevLett.125.117001.