Research found that novel materials are both thermally conductive and thermally insulated

Generally, the electrical resistance of a material largely depends on its physical size and basic properties. But in special cases, this resistance can take a fixed value independent of the basic properties and be "quantified" (meaning it changes in discrete steps rather than a continuous manner). This quantification of resistance usually occurs in environments with strong magnetic fields and low temperatures, and when electrons move in a two-dimensional manner.

Now, a research team led by the University of Göttingen has successfully demonstrated this effect in natural double-layer graphene (only two atoms thick) at low temperatures and almost no magnetic field. The results of this research have been published in the journal Nature.

The research team used natural double-layer graphene. The delicate graphene flakes are contacted using standard micromachining techniques. The flakes are positioned so that they hang freely like a bridge, and the edges are fixed by two metal contacts. In the extremely clean double-layer graphene, the electric resistance at low temperature is quantitative and the magnetic field is almost undetectable. In addition, the current flows without any energy loss.

The reason is a form of magnetic force, which is not generated in the usual way seen in traditional magnets (that is, through the arrangement of the internal magnetic moment of electrons), but is generated by the movement of the charged particles in the graphene double layer.

The researchers say that these particles generate their own inherent magnetic field, which leads to the quantification of resistance. This effect is special not only because it requires only one electric field, but also because it appears in eight different versions, which can be controlled by applying magnetic fields and electric fields. The effect can be turned on and off, and the direction of movement of the charged particles can be reversed.

Researchers believe that this discovery reveals possible application examples of graphene, such as the development of innovative computer components in the field of spintronics, which may have an impact on data storage. In addition, research can show this effect in a system composed of simple and naturally occurring materials, which is an advantage. This is in sharp contrast with the recently popular "heterostructure", which does not require a complex and precise composition of different materials.

Based on the current findings, further research is needed to find a way to stabilize it at higher temperatures, because the current research only occurs at five degrees above absolute zero.