Enormous enhancement of p-orbital magnetism and band gap in the lightly doped carbyne

TL;DR

This study demonstrates how doping in carbyne can significantly enhance p-orbital magnetism and band gap, enabling tailored magnetic and optical properties for advanced applications.

Contribution

It reveals that charge fluctuations induce enormous p-orbital magnetism and shows how specific dopants can convert carbyne into a magnetic and semiconducting material.

Findings

Arsenic doping increases magnetic moment to 2.9 Bohr Magneton.

Nitrogen and oxygen doping enlarge the band gap to 1.6 eV.

Magnetically optimized carbyne exhibits exchange-correlation energy of 22 meV.

Abstract

This paper presents a path to tailor adapted magnetic and optical properties in carbyne. Although p-orbital magnetism is generally much weaker than d-orbital magnetism, we demonstrate that the charge fluctuation of the free radical electrons triggered by a time-varying electric dipole moment leads to enormous p-orbital magnetism. By introducing 25% arsenic and 12.5% fluorine into the monoatomic carbon chain, the magnetic moment of the arsenic atom reaches 2.9 Bohr Magneton, which is ~1.3 times stronger than magnetic moment of bulk Fe. This magnetically optimized carbyne composite carries an exchange-correlation energy of 22meV (~270K). On the other hand, we convert the carbyne (in beta-form) from metallic to a semiconducting state by using anionic dopants. After doping 12.5% nitrogen and 12.5% oxygen into the beta-carbyne, the semiconducting gap of this composite is optimized at 1.6eV, which is 1.4 times larger than the band gap of bulk silicon.