Ricerc@Sapienza

The main aim of the project is the accurate characterization of the high-pressure superconducting phase diagram of a subset of complex boro-hydrides, with chemical formula ABH4, where A is an alkali metal or alkaline earth, which our preliminary results identify as a viable candidate for high-Tc superconductivity.
In particular, we will evaluate the possibility of stabilizing hydrogen-deficient phases (ABH3,ABH2), metallizing them by external pressure or doping, and estimate the relative critical temperature. In order to have accurate results, the vibrational properties will be evaluated within the stochastic self-consistent harmonic approximation (SSCHA). This will allow us to correctly take into account quantum lattice effects, which can have dramatic consequences on the superconducting phase diagram of hydrogen-rich solids.

The project combines two recently-established groups in theoretical condensed-matter physics, with complementary expertises in ab-initio crystal structure prediction and quantum lattice effects, which have been independently active in the study of superconductivity in high-pressure hydrides, since the ground-breaking report of high-Tc conventional superconductivity in SH3 in 2015.
The potential impact of the project is very high, in terms of purely scientific impact and international visibility. Indeed, the proposed topic is currently at the forefront of condensed matter research, because an improved understanding of possible mechanisms to achieve superconductivity above liquid nitrogen temperature in commercially-available materials has the potential to open a plethora of large-scale applications for superconductors, ranging from electrical grid components to magnetic levitation trains. In addition, the two groups have an extended network of international collaborators, which ensures a high visibility for the results of the collaboration.