Prof. Ion Errea [University of the Basque Country, Spain ]
Title: When are Hydrogen-Based Superconductors High-Tc Compounds?
Language: English presentation
Time: 15:30 - 17:00 PM, Tuesday, June 7th, 2022
Place: Tencent Meeting ID: 749-862-666
Host: Thomas Meier
Abstract
By analyzing structural and electronic properties of more than a hundred predicted hydrogen-based superconductors, we determine that the capacity of creating an electronic bonding network between localized units is key to enhance the critical temperature in hydrogen-based superconductors. We define a magnitude named as the networking value, which correlates with the predicted critical temperature better than any other descriptor analyzed thus far. By classifying the studied compounds according to their bonding nature, we observe that such correlation is bonding-type independent, showing a broad scope and generality. Furthermore, combining the networking value with the hydrogen fraction in the system and the hydrogen contribution to the density of states at the Fermi level, we can predict the critical temperature of hydrogen-based compounds with an accuracy of about 60 K, as shown in Fig. 1. Such correlation is useful to screen new superconducting compounds and offers a deeper understating of the chemical and physical properties of hydrogen- based superconductors, while setting clear paths for chemically engineering their critical temperatures.
References
[1]. F. Belli, T. Novoa, J. Contreras-García, I. Errea, Nat. Commun. 12, 5381 (2021).
Biography of the Speaker:
I was born in Donostia-San Sebastián, Basque Country, in 1984. I grew up in this beautiful city and I stayed there till I was 18. Then I moved to Bilbao to start my degree in physics in the University of the Basque Country (UPV/EHU).
After four years in Bilbao and an another year in the University of Groningen in the Netherlands, where I went with an Erasmus scholarship, I obtained my degree in physics in 2007.
Right after I graduated, I obtained a fellowship by the Basque Government to start a PhD project supervised by Aitor Bergara and Vyacheslav Silkin in the University of the Basque Country (UPV/EHU) and in the Donostia International Physics Center (DIPC). My thesis was entitled as Pressure induced complexity in simple elements and alloys from first-principles calculations and I defended it in 2011. You can download my thesis in English clicking here or in Basque in this link.
While I was writing my thesis I prepared a research project that I presented to the post-doctoral program of the Basque Government about Anharmonic effects in superconductors to be developed in the group of Francesco Mauri in the Institut de Minéralogie et de Physique des Millieux Condensés (IMPMC) at the Université Pierre et Marie Curie (UPMC) in Paris. My project was awarded with the fellowship and I worked for two years in Paris developing this project under the supervision of Francesco Mauri and Matteo Calandra. My main task was to develop the Stochastic Self-Consistent Harmonic Approximation (SSCHA).
In January 2014, I moved to the DIPC as a postdoctoral researcher to continue developing the SSCHA and applying it to systems of interests.
Since April 2015 I am a lecturer at the Department of Applied Physics 1 in the University of the Basque Country (UPV/EHU) and continue as an associate researcher of the DIPC.
In 2018 I joined the Materials Physics Center (Centro de Física de Materiales, CFM CSIC-UPV/EHU), where I lead the Quantum Theory of Materials group.
