Prediction of Half Metallicity along the Edge of Boron Nitride Zigzag Nanoribbons

TL;DR

First-principles calculations demonstrate that passivating the B edge of zigzag boron nitride nanoribbons induces half metallicity with 100% spin polarization, making them promising for spintronic applications.

Contribution

This work reveals that edge passivation in BN nanoribbons can induce half metallicity, a novel finding for pure $sp$-electron systems.

Findings

Electrons at the Fermi level are 100% spin polarized.

Half-metal gap of 0.38 eV observed.

Potential for BN nanoribbons in spintronics.

Abstract

First-principles calculations reveal half metallicity in zigzag boron nitride (BN) nanoribbons (ZBNNRs). When the B edge, but not the N edge, of the ZBNNR is passivated, despite being a pure $sp$-electron system, the ribbon shows a giant spin splitting. The electrons at the Fermi level are 100% spin polarized with a half-metal gap of 0.38 eV and its conductivity is dominated by metallic single-spin states. The two states across at the Dirac point have different molecular origins, which signals a switch of carrier velocity. The ZBNNR should be a good potential candidate for widegap spintronics.