Antiferromagnetic Skyrmionics: generating and controlling topological textures
ORAL · Invited
Abstract
Whirling magnetic textures could emerge as topologically protected information bits for next-generation computing. However, their practical adoption has been inhibited by susceptibility to stray fields, internal dipole fields, slow speed or sideway motion. To alleviate these issues, there has been a surge of interest in antiferromagnetic (AFM) analogues, predicted to be robust, scalable and ultra-fast. Yet, experimental progress in this field has been inhibited by the difficulty to visualize and control AFM textures via standard techniques.
To this effect, I will present a recently developed AFM vector-mapping technique1 to image variations of the AFM order. Then, I will outline a general field-free approach, employing the Kibble–Zurek transition, to reversibly create a wide multichiral family of topological AFM textures, including exotic (anti)merons, bimerons2. In epitaxial films and free-standing membranes of the earth-abundant oxide α-Fe2O3 these nanoscale textures can be nucleated and stabilized at room temperature. Particularly, the presence of widely tunable anisotropy3 and exchange1,2 interactions enable unprecedented reversible control over their dimensions and orientation. Then, I will present how we may realize the hitherto undiscovered AFM skyrmions in α-Fe2O3, by introducing new symmetry breaking interactions. Lastly, I will outline the path ahead for AFM skyrmionics, discussing how our results may be translatable to a broad class of AFM systems3,4, and sharing how electrical pathways can be exploited to control members of the topological family.
1. F Chmiel et al. Nat Mater 17, 581 (2018)
2. H Jani et al. Nature 590, 74 (2021)
3. H Jani et al. Nat Comm 12, 1668 (2021)
4. Z Lim, H Jani et al. MRS Bulletin, In Press (2021)
To this effect, I will present a recently developed AFM vector-mapping technique1 to image variations of the AFM order. Then, I will outline a general field-free approach, employing the Kibble–Zurek transition, to reversibly create a wide multichiral family of topological AFM textures, including exotic (anti)merons, bimerons2. In epitaxial films and free-standing membranes of the earth-abundant oxide α-Fe2O3 these nanoscale textures can be nucleated and stabilized at room temperature. Particularly, the presence of widely tunable anisotropy3 and exchange1,2 interactions enable unprecedented reversible control over their dimensions and orientation. Then, I will present how we may realize the hitherto undiscovered AFM skyrmions in α-Fe2O3, by introducing new symmetry breaking interactions. Lastly, I will outline the path ahead for AFM skyrmionics, discussing how our results may be translatable to a broad class of AFM systems3,4, and sharing how electrical pathways can be exploited to control members of the topological family.
1. F Chmiel et al. Nat Mater 17, 581 (2018)
2. H Jani et al. Nature 590, 74 (2021)
3. H Jani et al. Nat Comm 12, 1668 (2021)
4. Z Lim, H Jani et al. MRS Bulletin, In Press (2021)
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Publication: H Jani*, et al. Antiferromagnetic half-skyrmions and bimerons at room temperature. Nature 590, 74 (2021);<br>H Jani*, et al. Reversible hydrogen control of antiferromagnetic anisotropy in α-Fe2O3. Nature Communications 12, 1668 (2021)<br>ZS Lim^, H Jani^ et al. Skyrmionics in correlated oxides. MRS Bulletin (In Press, 2021)<br>J Harrison, H Jani et al. A route towards stable homochiral topological textures in A-type antiferromagnets. (To be submitted)<br><br>*Corresponding Author<br>^Equal Contribution
Presenters
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Hariom K Jani
Natl Univ of Singapore
Authors
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Hariom K Jani
Natl Univ of Singapore