Electron-phonon coupling strength from ab initio frozen-phonon approach

TL;DR

The paper introduces a rapid ab initio method to estimate electron-phonon coupling at zone-center phonon modes, aiding high-throughput screening of potential superconductors, and compares it with existing methods using MgB2 and hydrides.

Contribution

It presents a new efficient approach for estimating electron-phonon coupling focusing on zone-center modes, complementing existing Brillouin zone methods for superconductor discovery.

Findings

The method accurately estimates electron-phonon coupling for MgB2.

It effectively screens binary hydrides for superconductivity potential.

Comparison shows the method's advantages over the RMT approach.

Abstract

We propose a fast method for high-throughput screening of potential superconducting materials. The method is based on calculating metallic screening of zone-center phonon modes, which provides an accurate estimate for the electron-phonon coupling strength. This method is complementary to the recently proposed Rigid Muffin Tin (RMT) method, which amounts to integrating the electron-phonon coupling over the entire Brillouin zone (as opposed to the zone center), but in a relatively inferior approximation. We illustrate the use of this method by applying it to MgB$_\text{2}$, where the high-temperature superconductivity is known to be driven largely by the zone-center modes, and compare it to a sister compound AlB$_\text{2}$. We further illustrate the usage of this descriptor by screening a large number of binary hydrides, for which accurate first-principle calculations of electron-phonon coupling have been recently published. Together with the RMT descriptor, this method opens a way to perform initial high-throughput screening in search of conventional superconductors via machine learning or data mining.