Multiple Hall Effects in Antiferromagnetic-Ferroelectric Heterostructures.

Abstract

Distinct Hall effects are crucial for both theoretical study and practical applications in spintronics, valleytronics, and layertronics, but effectively controlling these effects in 2D antiferromagnets remains challenging. Here, a novel mechanism for achieving controllable Hall effects is proposed in A-type bilayer antiferromagnets sandwiched between ferroelectric layers. Based on a tight-binding model analysis, we demonstrate that by selectively reversing the polarization orientation of top or bottom ferroelectric layer, the bilayer antiferromagnets exhibit transitions between layer Hall, layer spin Hall, and valley layer spin Hall effects, driven by <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>P</mi><mi>T</mi></math> symmetry breaking or restoration as well as relative shift between antiferromagnetic and ferroelectric bands. First-principles calculations further verify the feasibility of this mechanism in the Al₂S₃/bilayer 2H-FeBr₂/Al₂S₃ multiferroic van der Waals heterostructure. These findings open a new avenue for manipulating Hall effects in layered antiferromagnets.