PRESS RELEASE
An international research team, involving researchers of RICMASS, shows that heterogeneous systems not only display fascinating phenomena such as the emergence of life made of jiggling atoms in the cell, and the self organization of social networks, bur also could favor the emergence of a macroscopic quantum coherent state of many particles at high temperature. New experimental results, published in the NATURE issue of 17 Sept 2015, show that superconductivity at high temperature takes advantage from a non Euclidean space created by intertwining of inhomogeneity of charge density wave order and material complexity.
One of the biggest challenge in this last century till now is to understand the mechanism favoring high temperature superconductivity. In superconductors the strange QUANTUM MATTER leaves the atomic and nuclear microscopic world to show up in the macroscopic world. In this a state of matter the electrons in a metal form a collective quantum condensate so that the electric resistance is zero at temperature lower than a critical value, Tc. Unfortunately the quantum theory applied to the case of a homogenous metal with a single electronic component predict that superconductivity occurs only at very low temperature near zero kelvin (-273 °C). However the recent experiments by Drozdov et al. on the Nature issue of 17 August, 2015 show that superconductivity could be present also at -70 °C, above the coldest temperature reached in Antartica. Superconductivity is currently used in a variety of technologies, such as in Magnetic Resonance Imaging, however the present superconductors needs to be significantly cooled since the critical temperatures are well below the room temperature. Therefore, finding new materials that are superconducting at room temperatures will transform our everyday life, allowing new technologies using quantum physics. Therefore scientists are looking today for protocols to design of new room temperature superconductors. The problem has been elusive for scientists since these phenomena involve both pairing at atomic level and coherence at macroscopic level, and they suffered for the lack of experimental microscopes to see the “Middle World”, the world between atomic and macroscopic world.
This gap has been filled by an international research project coordinated by the Rome International Center for Materials Science Superstripes RICMASS. The key tools of the experiment are synchrotron radiation X-rays beams focused down to the smallest size and the manipulation of “big data” sets.
The x-ray imaging has been achieved by the joint use of the most advanced experimental stations at the dedicated X-Ray Diffraction beam lines of the synchrotron radiation facilities:
European Synchrotron Radiation Facility, , ESRF, at Grenoble, France;
Synchrotron radiation facility Elettra at Trieste, Italy;
and
Deutsches Elektronen-Synchrotron (DESY) at Hamburg, Germany.
The scientific outcome is due to the a collaboration between top level institutions which have contributed to sample synthesis, their characterization and data analysis:
MESA1 Institute for Nanotechnology, University of Twente, AE Enschede, The Netherlands;
EPFL, Institute of Condensed Matter Physics, Lausanne Switzerland;
ETH, Swiss Federal Institute of Technology Zurich Laboratory for Solid State Physics, Zurich, Switzerland;
Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia;
Department of Analytical Chemistry, Ghent University, Ghent, Belgium;
Institute of Crystallography, Sincrotrone Elettra UOS Trieste,
with the key contributions to "big data"analysis and interpretation of the
Institute of Crystallography, CNR, Monterotondo Roma,
and the
School of Mathematics, Queen Mary University of London, London UK
Campi et al. now found that one of the best ceramic materials, superconductor at 95 K, displays a significant complexity and inhomogeneity, and that this aspect of their heterogeneous structural and electronic structure is favoring the superconducting state. These results bring a completely new perspective for the design of new room temperature superconductors. Advances in this field has been stopped for many years by homogeneity assumptions because of lack of experimental information on the complex structure of this intermediate world. Antonio Bianconi says: “Inhomogeneities are essential to sustaining high temperature superconductivity. This is a state of matter at high temperature that takes advantage of heterogeneity and complexity. In some way this phenomena could be compared with state of living matter. A protein folded state is another way to take advantage of complexity. The results by Campi et al. show a hyperbolic geometry (a non Euclidean space) favoring the emergence of macroscopic quantum world at high temperature.
1) Campi et al., Nature 525, 359–362 (17 Sept 2015)