Spatially Reconfigurable Antiferromagnetic states in Topologically-Rich Freestanding Nanomembranes

Antiferromagnets hosting real-space topological textures are promising platforms to model fundamental ultrafast phenomena and explore spintronics. However, to date, they have only been fabricated epitaxially on specific symmetry-matched substrates, to preserve their intrinsic magneto-crystalline order [1,2]. This curtails their integration with dissimilar supports, markedly restricting the scope of fundamental and applied investigations. Here, we circumvent this limitation by designing detachable crystalline antiferromagnetic nanomembranes of α-Fe₂O₃, that can be transferred onto other desirable supports after growth [3]. First, we show that flat nanomembranes host a spin reorientation transition and rich topological phenomenology via transmission-based antiferromagnetic vector-mapping. Second, we exploit the extreme flexibility of oxide membranes to demonstrate reconfiguration of antiferromagnetic states across three-dimensional membrane ‘folds’ resulting from flexure-induced strains. Finally, we combine these developments using an in-situ strain manipulator to realise the first demonstration of non-thermal Kibble-Zurek-like generation of topological textures at room temperature. Integration of such freestanding antiferromagnetic layers with flat/curved nanostructures could enable spin texture designs via magnetoelastic-/geometric-effects in the quasi-static and dynamical regimes, opening new explorations into curvilinear antiferromagnetism and unconventional computing.<br/><br/><br/>References:<br/>[1] <u>H Jani</u> et al., Nature 590, 74 (2021).<br/>[2] AKC Tan*, <u>H Jani</u>* et al., arXiv:2303.12125 (2023) [In Press - Nature Materials].<br/>[3] <u>H Jani</u>*, J Harrison* et al., arXiv:2303.03217 (2023) [In Review].