Dipartimento di Fisica

An international collaboration involving researchers from the Department of Physics at Sapienza, L'Aquila University, the Max-Planck-Institute for microstructure physics in Halle, the Max-Planck-Institute for Chemical Physics in Mainz and in the University of Tokyo has just published one of the most complete reviews on the field of high-temperature superconductivity at high pressures.  The field of superconductivity has been galvanized by reports of critical temperatures of 203 K (2015) and 260 K (2019) in two hydrogen-based materials. These two reports have broken the previous records held by the cuprates, providing the first glimpse to the solution of the hundred-year-old problem of room-temperature superconductivity.

Sulfur hydride (H3S, 2015) and lanthanum hydride (LaH10, 2019) belong to a unique class of materials, superhydrides, which do not usually exist in  standard thermodynamic conditions of pressure. In fact, both materials can only be synthesized at megabar pressures (over a million times higher than atmospheric pressures), which makes their study even more challenging and exciting.  The discovery of these hydrides is the result of a decade-long quest,  which required significant developments in high-pressure experimental research, the theory of superconductivity, and computational methods for crystal structure prediction, and represents a paradigm shift in the field of materials design. In the Review, published open access on Physics Reports, the authors, Jose A. Flores-Livas, Lilia Boeri and collaborators, explain the mechanism underlying superconductivity in these exceptional compounds and provide a complete reference of the recent advances in experimental techniques, superconductivity theory and first-principles computational methods which have made these discoveries possible.

Besides, in an attempt to evidence empirical rules governing superconductivity in hydrides under pressure, the authors of La Sapienza also discuss general trends in the electronic structure and chemical bonding, possible strategies to optimize pressure and transition temperatures in conventional superconducting materials as well as future directions in theoretical, computational and experimental research.  In the words of the Referees, this work has been classified as "one of the most complete, and  up-to-date Review on the superconductivity of Hydrides, that will definitely serve as a reference for future works." 

References:
A Perspective on Conventional High-Temperature Superconductors at High Pressure: Methods and Materials.

Authors
José A. Flores-Livas,  Lilia Boeri, Antonio Sanna, Gianni Profeta, Ryotaro Arita, Mikhail Eremets - Physics Reports Volume 856, 29 April 2020, Pages 1-78.

OPEN ACCESS.   Info:  José A. Flores-Livas,  Dipartimento di Fisica,  jose.flores@uniroma1.it