Realizing intrinsic Chern half-metallicity and large anomalous Hall conductivity in 2D BaNiCl ₃

Abstract We report atomically thin BaNiCl 3 , a layered halide perovskite, as a rare intrinsic Chern half-metal from first-principles calculations. The system exhibits complete spin polarization with a high Chern number ( C = 2), a sizable anomalous Hall conductivity of 316 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msup> <mml:mi mathvariant="normal">Ω</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mo>,</mml:mo> <mml:msup> <mml:mrow> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> , and ultrafast carrier dynamics with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>v</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">F</mml:mi> </mml:mrow> </mml:msub> <mml:mo>≈</mml:mo> <mml:mn>0.78</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>6</mml:mn> </mml:msup> </mml:mrow> </mml:math> m s −1 . Spin–orbit coupling opens a 20 meV bandgap, generating strong Berry-curvature hotspots that enhance Hall response. Ferromagnetism is stabilized by the Ni 2+ ( d 8 ) configuration and Cl-mediated superexchange. This combination of half-metallicity, SOC-induced topology, and robust anomalous Hall transport positions BaNiCl 3 as a promising 2D platform for dissipationless spintronics and quantum technologies.