• Sun. Nov 28th, 2021

Electricity revolution, towards superconductors that could cut costs


Oct 27, 2021

The results of the international research on the superconductor at room temperature, the material that could revolutionize technologies, reducing the energy costs of electricity distribution and changing the very structure of the system of production and distribution of electricity in the world have landed in ‘Science’ . The study makes, in fact, less mysterious the ‘strange’ behavior of cuprates, superconducting materials composed of copper, oxygen and other elements that however ‘work’ only at very low temperatures. This opens the way to a real electricity revolution. Scientists from the Chalmers University of Gothenburg, the Polytechnic University of Milan, the Sapienza University of Rome and the European Synchrotron ESRF have indeed discovered that, in the normal state, the presence of charge density waves modifies the ‘strange metal’ behavior of the cuprates and leads it to be more similar to that of normal metals. Superconductors are materials in which electric current travels without resistance below a certain temperature. This, explain the Polytechnic of Milan and the Chalmers University, “drastically differentiates them from normal metals in which resistance involves a production of heat and therefore a waste of energy when a current flows”. Although known for more than a century, superconductivity remains one of the most mysterious and fascinating phenomena studied in the physics of solids. And the researchers’ goal is precisely to find materials that are superconducting at normal temperatures. The researchers of the PoliMi and of the University of Chalmers recall that “an important property of cuprates – given by the fact that, even at a temperature above the critical one, when they are in the ‘normal’ state and therefore have no resistance to zero – is that they behave in an unconventional way, to the point of being called ‘strange’ metals “. And “the strangeness – they continue – lies in the linear increase in resistivity with temperature, which is not usually the case for normal metals”. Understanding the ‘strangeness’ of the ‘normal’ state of superconducting cuprates is one of the goals of international research in this field in recent years. “This type of observation is of great relevance because it finally shows a correlation between macroscopic properties (resistivity in the normal state , superconductivity) and microscopic properties (the charge density waves) “explains Professor Giacomo Ghiringhelli, professor of Experimental Physics at the Politecnico di Milano. “This – he adds – may be the key to the problem long sought by theorists, a sure basis on which to finally build the explanation of the very original behavior of superconducting cuprates”. To understand the importance of the thing, experts invite us to consider that “superconductivity is the most spectacular macroscopic manifestation, visible to the naked eye, of quantum physics, indispensable for describing phenomena on the atomic scale, but usually not on the macroscopic one. However, superconductivity is a macro-quantum phenomenon. Now it turns out that even at high temperatures, in the ‘normal’ state, cuprates have a quantum behavior, so we can speak of ‘ultra-quantum’ matter “.