Magnetic topological textures in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>BiFeO</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:math> with ferroelectric domain walls

Topological defects in ferroic materials are attracting significant attention due to their role as a platform for distinctive physical phenomena and their potential applications in electronic devices. Bismuth ferrite stands out as a well-known multiferroic material, exhibiting both ferroelectric and antiferromagnetic properties at room temperature. While magnetic topological defects in bismuth ferrite begin to be well documented, the influence of cycloids with different propagation directions on the magnetic structure at ferroelectric domain walls remains relatively unexplored. In this study, we employ a first-principles-based effective Hamiltonian method in conjunction with Monte Carlo simulations to predict the formation of distinct magnetic textures at ferroelectric domain walls. An analysis of the Pontryagin charge density reveals them to be localized Bloch points, merons, and homogeneous Pontryagin charge-density tubes, which hold promise for future usage in electronic devices.