1. Observation of room-temperature polar skyrmions.
- Author
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Das, S, Tang, YL, Hong, Z, Gonçalves, MAP, McCarter, MR, Klewe, C, Nguyen, KX, Gómez-Ortiz, F, Shafer, P, Arenholz, E, Stoica, VA, Hsu, S-L, Wang, B, Ophus, C, Liu, JF, Nelson, CT, Saremi, S, Prasad, B, Mei, AB, Schlom, DG, Íñiguez, J, García-Fernández, P, Muller, DA, Chen, LQ, Junquera, J, Martin, LW, and Ramesh, R
- Subjects
MD Multidisciplinary ,General Science & Technology - Abstract
Complex topological configurations are fertile ground for exploring emergent phenomena and exotic phases in condensed-matter physics. For example, the recent discovery of polarization vortices and their associated complex-phase coexistence and response under applied electric fields in superlattices of (PbTiO3)n/(SrTiO3)n suggests the presence of a complex, multi-dimensional system capable of interesting physical responses, such as chirality, negative capacitance and large piezo-electric responses1-3. Here, by varying epitaxial constraints, we discover room-temperature polar-skyrmion bubbles in a lead titanate layer confined by strontium titanate layers, which are imaged by atomic-resolution scanning transmission electron microscopy. Phase-field modelling and second-principles calculations reveal that the polar-skyrmion bubbles have a skyrmion number of +1, and resonant soft-X-ray diffraction experiments show circular dichroism, confirming chirality. Such nanometre-scale polar-skyrmion bubbles are the electric analogues of magnetic skyrmions, and could contribute to the advancement of ferroelectrics towards functionalities incorporating emergent chirality and electrically controllable negative capacitance.
- Published
- 2019