In a statement, FCUP explains that the new three-dimensional (3D) materials are Dirac-Weyl semimetals, a set of synthetic crystals, produced in the laboratory, whose electronic properties may allow their use "in the computers of the future".
"These crystals are three-dimensional and present a rare characteristic: electrons that behave as if they had no mass", clarifies the institution.
The materials, which are believed to be "more robust than graphene", may become insensitive to random conditions, such as the presence of impurities.
Quoted in the document, João Pedro Pires, a researcher at FCUP, says this "rare" characteristic has "many consequences on electrical conductivity", as they are "extremely good conductors".
"The first theoretical studies were made assuming that the crystal was perfect. The same thing had happened with graphene, but in 2014 it was first put into question whether the physics of electrons would change when crystals have imperfections, as is known to happen in real graphene samples," he says.
To answer questions such as whether imperfections in the crystal turn this semi-metal into a conventional metal or whether the impurities produced will destroy the electronic characteristics in these materials, the researchers started the study in 2019.
It was at the University of Central Florida (USA), where the Portuguese researcher was as part of his PhD and where these materials were discovered, that the theoretical study began.
In the scope of the research, published in the American journal 'Physical Review Research', the researchers concluded that these semi-metals are "unstable to disorder" and that there is an "exponentially small change that transforms them into normal metals in the presence of impurities".
For this, it is "fundamental" to use the QuantumKITE software, developed in 2018 by two FCUP researchers, which allows an efficient simulation of quantum matter.
The question now is whether the "level of smallness of the effect is relevant or not to make it unfeasible" for this type of materials to be applied to new quantum technologies.
In this sense, the next step of the research is to study the effect of different defect models with the aim of "guiding the production optimisation of these materials, taking into account possible constraints on their technological application".
"If the main issue is only in impurities, researchers can use a cleaner room to produce these crystals", clarifies João Pedro Pires, adding that one of the challenges associated with quantum computers is their "great sensitivity" to temperature and impurities.
Such sensitivity can also be applied to new types of sensors, such as infrared radiation or ultrafast laser components, where this factor assumes great importance.
Started in 2019, the study, recently published, integrated researchers from the University of Minho, University of York (England), University of Central Florida (USA), University of Twente (Netherlands) and University of Sabanci-Tulsa (Turkey).