Nature of the electronic states involved in the chemical bonding and superconductivity at high pressure in SnO

TL;DR

This study uses density functional theory to analyze the electronic structure of SnO under high pressure, revealing how pressure induces metallic states and potential mechanisms for superconductivity involving Fermi surface nesting.

Contribution

It provides a detailed DFT-based analysis of electronic states in SnO under pressure, linking electronic structure changes to superconductivity mechanisms.

Findings

Sn valence states are strongly hybridized with O 2p-states.

Metallic states emerge under pressure due to transformation of O 2p-Sn 5sp subband.

Electronic states involved in bonding and Fermi surface nesting may facilitate superconductivity.

Abstract

We have investigated the electronic structure and the Fermi surface of SnO using density functional theory (DFT) calculations within recently proposed exchange-correlation potential (PBE+mBJ) at ambient conditions and high pressures up to 19.3 GPa where superconductivity was observed. It was found that the Sn valence states 5s, 5p, and 5d are strongly hybridized with the O 2p-states, and that our DFT-calculations are in good agreement with O K-edge X-ray spectroscopy measurements for both occupied and empty states. It was demonstrated that the metallic states appearing under pressure in the semiconducting gap stem due to the transformation of the weakly hybridized O 2p-Sn 5sp subband corresponding to the lowest valence state of Sn in SnO. We discuss the nature of the electronic states involved in chemical bonding and formation of the hole and electron pockets with nesting as a possible way to superconductivity.