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Observation of room-temperature polar skyrmions


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 responses. 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.

 Fuente: Nature volume 568, pages368-372(2019)

Editorial: Nature Publishing Group

 Fecha de publicación: 01/04/2019

Nº de páginas: 17

Tipo de publicación: Artículo de Revista

ISSN: 0028-0836,1476-4687

Proyecto español: FIS2015-64886-C5-2-P

Url de la publicación: https://doi.org/10.1038/s41586-019-1092-8

Autores/as

DAS, S.
TANG, Y.L.
HONG, Z.
GONÇALVEZ, M.A.P.
MCCARTER, M.R.
KLEWE, C.
NGUYEN, K.X.
SHAFER,P.
ARENHOLZ, E.
STOICA, V.A.
HSU, S-L.
WANG, B.
OPHUS, C.
LIU, J.F.
NELSON, C.T.
SAREMI, S.
PRASAD, B.
MEI, A.B.
SCHLOM, D.G.
ÍÑIGUEZ, J.
MULLER, D.A.
CHEN, L.Q.
RAMESH, R.