%0 Journal Article
%K transmission electron microscopy
%K room temperature
%K Polarization
%K Magnetism
%K electric field
%K priority journal
%K titanium
%K chirality
%K circular dichroism
%K electric activity
%K electric capacitance
%K electromagnetism
%K Letter
%K scanning transmission electron microscopy
%K X ray diffraction
%A S Das
%A Y.L Tang
%A Z Hong
%A M.A.P Gonçalves
%A M.R McCarter
%A C Klewe
%A K.X Nguyen
%A F Gómez-Ortiz
%A P Shafer
%A E Arenholz
%A V.A Stoica
%A S.-L Hsu
%A B Wang
%A C Ophus
%A J.F Liu
%A C.T Nelson
%A S Saremi
%A B Prasad
%A A.B Mei
%A D.G Schlom
%A J Íñiguez
%A P García-Fernández
%A D.A Muller
%A L.Q Chen
%A J Junquera
%A L.W Martin
%A Ramamoorthy Ramesh
%B Nature
%D 2019
%G eng
%I Nature Publishing Group
%P 368-372
%R 10.1038/s41586-019-1092-8
%T Observation of room-temperature polar skyrmions
%V 568
%X 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.