Shao, Y-T and Das, S and Hong, Z and Xu, R and Chandrika, S and Gómez-Ortiz, F and GarcÃa-Fernández, P and Chen, L-Q and Hwang, HY and Junquera, J and Martin, LW and Ramesh, R and Muller, DA (2023) Emergent chirality in a polar meron to skyrmion phase transition. In: Nature Communications, 14 (1).
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Abstract
Polar skyrmions are predicted to emerge from the interplay of elastic, electrostatic and gradient energies, in contrast to the key role of the anti-symmetric Dzyalozhinskii-Moriya interaction in magnetic skyrmions. Here, we explore the reversible transition from a skyrmion state (topological charge of −1) to a two-dimensional, tetratic lattice of merons (with topological charge of −1/2) upon varying the temperature and elastic boundary conditions in [(PbTiO3)16/(SrTiO3)16]8 membranes. This topological phase transition is accompanied by a change in chirality, from zero-net chirality (in meronic phase) to net-handedness (in skyrmionic phase). We show how scanning electron diffraction provides a robust measure of the local polarization simultaneously with the strain state at sub-nm resolution, while also directly mapping the chirality of each skyrmion. Using this, we demonstrate strain as a crucial order parameter to drive isotropic-to-anisotropic structural transitions of chiral polar skyrmions to non-chiral merons, validated with X-ray reciprocal space mapping and phase-field simulations.
| Item Type: | Journal Article |
|---|---|
| Publication: | Nature Communications |
| Publisher: | Nature Research |
| Additional Information: | The copyright for this article belongs to the Authors. |
| Keywords: | boundary condition; mapping method; phase transition; polarization; simulation; temperature effect |
| Department/Centre: | Division of Chemical Sciences > Materials Research Centre |
| Date Deposited: | 02 May 2023 09:12 |
| Last Modified: | 02 May 2023 09:12 |
| URI: | https://eprints.iisc.ac.in/id/eprint/81236 |
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