Science and Technology Daily, Beijing, November 6 (Reporter Liu Xia) Swiss scientists published a paper in the latest issue of Nature Nanotechnology magazine that they made the first superconducting quantum interference device using graphene to demonstrate the interference of superconducting quasiparticles. The latest research is expected to promote the development of quantum technology and open up new possibilities for superconducting research.
Graphene came out in 2004, and since then, it has attracted wide attention and gained great development. Graphene is a new nano material with the thinnest, highest strength and best conductivity. With the continuous deepening of research, more characteristics of them have emerged one by one.
Double layer twisted graphene -- two atomic layers slightly twisted relative to each other is the focus of research in recent years. A year ago, Klaus Enslin's team from the Solid State Physics Laboratory of the Federal Institute of Technology in Zurich proved that twisted double-layer graphene can be used to manufacture Josephson junction, the basic component of superconducting equipment.
In the latest research, Enslin's scientific research team made the first superconducting quantum interference device (SQUID) using twisted graphene to demonstrate the interference of superconducting quasiparticles. Traditional SQUID is widely used in medicine, geology, archaeology and other fields. Its sensitive sensor can measure small changes in magnetic field, but it only works with superconducting materials, so it needs to use liquid helium or nitrogen for cooling when working.
The sensitivity of the newly developed graphene SQUID is not better than that of the traditional aluminum SQUID, and it must also be cooled to 2 ℃ above absolute zero. "However, the latest research has greatly expanded the application range of graphene. Previously, we have proved that graphene can be used to manufacture single electron transistors, and now superconducting equipment has been added." Enslin pointed out that "in quantum technology, SQUID can accommodate quantum bits, so it can be used as an element to perform quantum operations. In addition, in general, transistors are made of silicon and SQUID is made of aluminum. Different materials require different processing technologies, but now they can all be made of graphene. "
Ensling added that there are different superconducting phases in graphene, but there is no theoretical model to explain them. The latest achievements will also bring new possibilities for superconductivity research. With these components, it may be possible to better understand how superconductivity in graphene is generated.
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Graphene has a series of excellent properties: the thinnest material you can imagine, the material with the largest specific surface area, the strongest material known at present, the crystal with the strongest ductility and flexibility, and the thermal conductivity has also broken the existing records. Since its inception, graphene has attracted great attention from scientists in the field of materials, and new research and development achievements have emerged in endlessly. However, it has to be said that graphene has not been invented for a long time, and its mass production, preparation and industrial application are still under exploration. This is why, although we can "encounter" some graphene products in the market, it is not common. Of course, it is hard to hide the huge application potential of graphene, and we still need to give it more time.
