Observation of room-temperature polar skyrmions

Journal Article

Das, S, Y.L Tang, Z Hong, M.A.P Gonçalves, M.R McCarter, C Klewe, K.X Nguyen, F Gómez-Ortiz, P Shafer, E Arenholz, V.A Stoica, S.-L Hsu, B Wang, C Ophus, J.F Liu, C.T Nelson, S Saremi, B Prasad, A.B Mei, D.G Schlom, J Íñiguez, P García-Fernández, D.A Muller, L.Q Chen, J Junquera, L.W Martin, Ramamoorthy Ramesh

10.1038/s41586-019-1092-8

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. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.

Nature

568

2019

00280836

cited By 31

Ramesh Lab