Tiziana Musso1,Bin Xu2,Yousra Nahas3,Sergei Prokhorenko3,Daniel Sando4,1,Nagarajan Valanoor1,Laurent Bellaiche3
University of New South Wales1,Soochow University2,University of Arkansas, Fayetteville3,University of Canterbury4
Tiziana Musso1,Bin Xu2,Yousra Nahas3,Sergei Prokhorenko3,Daniel Sando4,1,Nagarajan Valanoor1,Laurent Bellaiche3
University of New South Wales1,Soochow University2,University of Arkansas, Fayetteville3,University of Canterbury4
As one of the most studied room-temperature multiferroics<sup>1</sup>, the perovskite compound bismuth ferrite (BiFeO<sub>3</sub> - BFO) has intriguing magnetic structures, where a Dzyaloshinskii-Moriya interaction results in complex spin cycloids. BFO’s appealing properties are not only photovoltaic, piezoelectric and optoelectronic, as different topological states have been recently found<sup>2</sup>. These particular phases provide a topological protection necessary for information storage technology<sup>3</sup>.<br/>In this work, a first-principles-based effective Hamiltonian approach<sup>4</sup> is used, in conjunction with Monte Carlo simulations, to investigate the magnetic properties of BFO under certain constraints.<br/>First, fast quenching simulations of BFO under strain reveal the presence of magnetic antiferromagnetic (AFM) skyrmions, quasiparticles topologically protected that form stable spin textures<sup>5</sup>. The Pontryagin density has been computed to unambiguously identify the topological nature of the obtained swirling field structures<sup>6</sup>. These novel AFM skyrmion patterns have different morphologies and are preferentially located at the ferroelectric domain walls.<br/>Subsequently, the topological structures obtained from cycloids with different initial propagation directions have been investigated, highlighting the interplay between polarization, cycloids and topological magnetic configurations.<br/><br/><br/>REFERENCES<br/><br/>1. Xu, B. <i>et al</i>. Revisiting spin cycloids in multiferroic BFO. Phys. Rev. B. 98 1–6 (2018)<br/>2. Govinden, V. <i>et al.</i> Spherical ferroelectric solitons. 1–9 (2023)<br/>3. Cortes-Ortuno, D. <i>et al.</i> Thermal stability and topological protection of skyrmions in nanotracks. Sci. Rep. 1–13 (2017)<br/>4. Rahmedov, D. <i>et al.</i> Magnetic Cycloid of BiFeO<sub>3</sub> from Atomistic Simulations. Phys. Rev. Lett. 109, 37207 (2012)<br/>5. Nagaosa, N. & Tokura, Y. Topological properties and dynamics of magnetic skyrmions. Nature Nanotech 8, 899–911 (2013)<br/>6. Nahas, Y. <i>et al.</i> Discovery of stable skyrmionic state in ferroelectric nanocomposites. Nat Comms 1–6 (2019)