NiCl3 Monolayer: Dirac Spin-Gapless Semiconductor and Chern Insulator

TL;DR

This paper predicts that NiCl3 monolayers are promising for room-temperature quantum anomalous Hall effects due to their large non-trivial band gap, high Curie temperature, and high carrier mobility, based on first-principles calculations.

Contribution

It introduces NiCl3 monolayer as a new class of Dirac material with potential for room-temperature QAH effects, combining large band gap and high magnetic ordering.

Findings

NiCl3 monolayer exhibits Dirac spin-gapless semiconducting behavior.

It becomes an insulator with a large non-trivial band gap (~24 meV) when considering spin-orbit coupling.

High mobility of Dirac fermions (~4x10^5 m/s) suggests excellent electronic properties.

Abstract

The great obstacle for practical applications of the quantum anomalous Hall (QAH) effect is the lack of suitable QAH materials (Chern insulators) with large non-trivial band gap, room-temperature magnetic order and high carrier mobility. The Nickle chloride (NiCl3) monolayer characteristics are investigated herein using first-principles calculations. It is reported that NiCl3 monolayers constitute a new class of Dirac materials with Dirac spin-gapless semiconducting and high-temperature ferromagnetism (~400K). Taking into account the spin-orbit coupling, the NiCl3 monolayer becomes an intrinsic insulator with a large non-trivial band gap of ~24 meV, corresponding to an operating temperature as high as ~280K at which the quantum anomalous Hall effect could be observed. The calculated large non-trivial gap, high Curie temperature and single-spin Dirac states reported herein for the NiCl3 monolayer lead us to propose that this material give a great promise for potential realization of a near-room temperature QAH effect and potential applications in spintronics. Last but not least the calculated Fermi velocities of Dirac fermion of about 4x105 m/s indicate very high mobility in NiCl3 monolayers.