Emergent chirality in a polar meron to skyrmion phase transition
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 13, 2023
- Source ID
- 10.1038/s41467-023-36950-x
Entities
People
- David A. Muller
- F Gómez-Ortiz
- Harold Y. Hwang
- Javier Junquera
- Lane W Martin
- Long-Qing Chen
- Pablo García-Fernández
- Ramamoorthy Ramesh
- Ruijuan Xu
- S Das
- Swathi Chandrika
- Yu‐Tsun Shao
- Zijian Hong
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- National Science Foundation