Superconductivity in heavily vacant diamond

TL;DR

This study uses first-principles calculations to explore how heavy doping and vacancies in diamond can create impurity bands, potentially leading to superconductivity, and provides a simplified model for further many-body analysis.

Contribution

It introduces a single-band effective Hamiltonian for vacancy-induced impurity bands in heavily doped diamond, enabling future studies of many-body effects.

Findings

Impurity bands form at 1-6% doping in diamond.

Vacancies create a single-band impurity band.

The effective Hamiltonian simplifies the study of disorder and many-body effects.

Abstract

Using first principle electronic structure calculations we investigated the role of substitutional doping of B,N,P,Al and vacancies (${\cal V}$) in diamond (X$_{\alpha}$C$_{1-\alpha}$). In the heavy doping regime, at about $\sim 1-6%$ doping an impurity band appears in the mid gap. Increasing further the concentration of the impurity substitution fills in the gap of the diamond host. Our first principle calculation indicates that in the case of vacancies, a clear single-band picture can be employed to write down an effective {\em one band} microscopic Hamiltonian, which can be used to further study various many-body and disorder effects in impurity band (super)conductors.