Tunable Magnetic Semiconductor Behavior Driven by Half-Filled One Dimensional Band in Zigzag Phosphorene Nanoribbons

TL;DR

This study reveals that zigzag phosphorene nanoribbons exhibit tunable magnetic and electronic properties driven by half-filled one-dimensional bands, with potential applications in nanoelectronics.

Contribution

It uncovers the mechanism behind magnetic and electronic tunability in ZPNRs due to half-filled bands, a novel insight for 1D magnetic semiconductors.

Findings

Antiferromagnetic insulating state in ZPNRs.

Magnetism stable with large band gap (~0.7 eV).

Strain induces magnetic and electronic phase transitions.

Abstract

An antiferromagnetic insulating state has been found in the zigzag phosphorene nanoribbons (ZPNRs) from a comprehensive density functional theory calculations. Comparing with other one-dimensional systems, the magnetism in ZPNRs display several surprising characteristics: (i) the magnetic moments are antiparallel arranged at each zigzag edge; (ii) the magnetism is quite stable in energy (about 29 meV/magnetic-ion) and the band gap is big (about 0.7 eV); (iii) a moderate compressive strain will induce a magnetic to nonmagnetic as well as semiconductor to metal transition. All of these phenomena arise naturally due to one unique mechanism, namely the electronic instability induced by the half-filled one dimensional bands which cross the Fermi level at around {\pi}/2a. The unusual electronic and magnetic properties in ZPNRs endow them great potential for the applications in nanoelectronic devices.