Scientists have succeeded in combining 2 exciting materials together for the very first time: an ultrathin semiconductor just one atom thick; and a superconductor, capable of conducting electricity with zero resistance.
Both these materials have unusual and interesting properties, and by putting them together through a fragile lab fabrication process, the team behind the research is hoping to open up all types of latest applications in classical & quantum physics .
Semiconductors are key to the electrical gadgets that dominate our lives, from TV to phones. What makes them so useful as against regular metals is their electrical conductivity are often adjusted by applying a voltage to them (among other methods), making it easy to switch current-flow on & off.
Here, one layer of the semiconductor molybdenum disulfide (MoS2) was extracted and added to the fabrication process.
Then we’ve superconductors – ready to transfer an electrical charge with perfect efficiency & nothing lost to heat, when at a particular temperature (usually a particularly low one).
In this setup, a superconductor called molybdenum rhenium (MoRe) was added to the device, and therefore researchers expect to observe completely new physical phenomena from their combined materials.
“In a superconductor , the electrons arrange themselves into pairs, like partners in dance – with weird & wonderful consequences, like the flow of the electrical current without a resistance,” says physicist Andreas Baumgartner, from the University of Basel in Switzerland.
“In the semiconductor molybdenum disulfide, on the opposite hand, the electrons perform a totally different dance, a wierd solo routine that also incorporates their magnetic moments. Now we might wish to determine which new & exotic dances the electrons agree upon if we combine these materials.”
Ultrathin semiconductors just like the one used here are currently a hot investigation topic for researchers: they can be stacked together to make entirely new synthetic materials referred to as van der Waals heterostructures.
These structures have tons of probably innovative uses, like having the ability to regulate electron magnetism with electric fields. However, tons of this potential remains theoretical, because scientists just do not know what effects they going to-get yet & what devices they could be ready to make. Which is why succeeding in creating this latest combination is so important.
In this latest setup, the team found evidence of strong coupling (interactions referred to as the proximity effect) between the semiconductor layer and therefore the superconductor, when the materials were cooled right down to just above temperature (-273.15°C or -459.67°F).
“Strong coupling may be a key element within the new & exciting physical phenomena that we expect to ascertain in such van der Waals heterostructures, but were never ready to demonstrate,” says physicist Mehdi Ramezani, from the University of Basel.
Getting this semiconductor-superconductor link together isn’t easy – as you’d expect, considering nobody has done it before. The semiconductor is placed in sandwich, with insulating layers above and below, while holes etched within the top of the insulating layer provide the contact access.
The superconducting material fills the gaps left by the holes, and therefore the process is finished inside a nitrogen-filled glove box to guard the finished system from damage. Remote-controlled micromanipulators are wont to complete the fabrication, under an optical microscope.
With the fabrication now achieved, the testing and therefore the experiments can begin – and have already started, in refrigerators cooled near by absolute zero . What’s more, the researchers think that they might use an equivalent technique to figure with other semiconductors within the future, further expanding its potential.
“Our measurements show that these hybrid monolayer semiconductor components are indeed possible – maybe even with other, more exotic contact materials that might pave the way for further insights,” says Baumgartner.
The research has been published in Nano Letters.