Universal scaling law for chiral antiferromagnetism.

Abstract

The chiral antiferromagnetic (AFM) materials, which have been widely investigated due to their rich physics, such as non-zero Berry phase and topology, provide a platform for the development of antiferromagnetic spintronics. Here, we find two distinctive anomalous Hall effect (AHE) contributions in the chiral AFM Mn₃Pt, originating from a time-reversal symmetry breaking induced intrinsic mechanism and a skew scattering induced topological AHE due to an out-of-plane spin canting with respect to the Kagome plane. We propose a universal AHE scaling law to explain the AHE resistivity ( <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub><mrow><mi>ρ</mi></mrow> <mrow><mi>A</mi> <mi>H</mi></mrow> </msub> </math> ) in this chiral magnet, with both a scalar spin chirality (SSC)-induced skew scattering topological AHE term, <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub><mrow><mi>a</mi></mrow> <mrow><mi>s</mi> <mi>k</mi></mrow> </msub> </math> and non-collinear spin-texture induced intrinsic anomalous Hall term, <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub><mrow><mi>b</mi></mrow> <mrow><mi>i</mi> <mi>n</mi></mrow> </msub> </math> . We found that <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub><mrow><mi>a</mi></mrow> <mrow><mi>s</mi> <mi>k</mi></mrow> </msub> </math> and <math xmlns="http://www.w3.org/1998/Math/MathML"> <msub><mrow><mi>b</mi></mrow> <mrow><mi>i</mi> <mi>n</mi></mrow> </msub> </math> can be effectively modulated by the interfacial electron scattering, exhibiting a linear relation with the inverse film thickness. Moreover, the scaling law can explain the anomalous Hall effect in various chiral magnets and has far-reaching implications for chiral-based spintronics devices.