Researchers combined ultrathin semiconductors with superconducting contacts, paving the road for future electronic devices.
Semiconductors are the material of choice for electronic devices as they provide us control that metals do not. In semiconductors, it is possible to adjust their electrical conductivity by applying a voltage and hence to switch the current flow on and off.
For future applications such as quantum computers, researchers are focusing on the development of new components that consist of a single layer (monolayer) of a semiconducting material. The ultrathin semiconductors offer unique characteristics that are otherwise very difficult to control, such as the use of electric fields to influence the magnetic moments of the electrons. Moreover, complex quantum mechanical phenomena take place in these semiconducting monolayers that may have applications in quantum technology.
Researchers from the University of Bassel have implemented an ultrathin semiconductor equipped with superconducting contacts. These ultrathin materials demonstrate unique optical and electrical properties that could pave the road for future electronic devices. According to the researchers, with the superconducting contacts, they are expected to give rise to new quantum phenomena and find use in quantum technology.
“In a superconductor, the electrons arrange themselves into pairs, like partners in a dance – with weird and wonderful consequences, such as the flow of the electrical current without a resistance,” Baumgartner, the project manager of the study, explains why this combination of ultrathin semiconductor and superconductor is so interesting . “In the semiconductor molybdenum disulfide, on the other hand, the electrons perform a completely different dance, a strange solo routine that also incorporates their magnetic moments. Now we would like to find out which new and exotic dances the electrons agree upon if we combine these materials.”
The researchers observed the superconducting property at low temperatures, and also found indications of a strong coupling between the semiconductor layer and the superconductor.
“Strong coupling is a key element in the new and exciting physical phenomena that we expect to see in such van der Waals heterostructures, but were never able to demonstrate,” says Mehdi Ramezani, lead author of the study.
The thin semiconductors stacked to form a new synthetic material is known as van der Waals heterostructure.
“And, of course, we always hope for new applications in electronics and quantum technology,” says Baumgartner. “In principle, the vertical contacts we’ve developed for the semiconductor layers can be applied to a large number of semiconductors. Our measurements show that these hybrid monolayer semiconductor components are indeed possible –perhaps even with other, more exotic contact materials that would pave the way for further insights,” he adds.