Superconductivity refers to those materials which contain specific physical properties wherein electrical resistance and magnetic flux fields are excluded from the material. All materials having these types of properties can be referred as a superconductor. In contrast to the ordinary metallic conductor, whose resistance gradually diminishes as the temperature is lowered down to near zero, a superconductor instead is critical to a temperature below which the resistance abruptly goes down to zero.
Now, a research team has discovered a unique superconducting metal that is much more resilient when used as an extremely thin layer. The research is a big advancement for Superconducting Materials Market as it can be considered as the first step towards developing a foundation in unconventional superconducting states in materials that could help in quantum computing shortly.
Niobium diselenide (NbSe2) is known as a superconducting metal denoting that it has the ability to conduct electricity and can also transport electrons from one atom to another without any resistance. Although it is normal for materials to behave differently when they are very small, NbSe2 has been noticed to have beneficial properties. The team discovered that the material in 2D (meaning as a fragile substrate which is only a few atomic layers thick) forms are more resilient as a superconductor as it has a two-fold symmetry. This characteristic is very different when more viscous samples of the same model were taken.
The researchers stated that the newly discovered two-fold rotational symmetry of the NbSe2, while it is a superconducting state, is mainly due to mixing. They were referring to the two closely competing types of superconductivity. First is the traditional s-wave type (typical of bulk NbSe2). The second is the unorthodox d-type or p-type mechanism that arises in some layers of NbSe2. Both these types of superconductivities have the same kind of energies in this system. This is mainly the reason for them to interact and compete like this.
The research team investigated atomically thin 2D superconducting devices. They expected it to have a six-fold rotational pattern similar to a snowflake. However, despite the six-fold structure, they noticed that it only showed two-fold behavior in the tests. For the first time, this phenomenon was seen in the actual material.
The team is now planning on building upon their initial results to explore further the properties of NbSe2 in combination with other unconventional 2D materials. The investigation might one day help in the use of unconventional superconducting states like topological superconductivity to build quantum computers.