Skip to main content

NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Local negative permittivity and topological-phase transition in polar skyrmions

Published

Author(s)

Sujit Das, Zijian Hong, Vladimir Stoica, Mauro A. Goncalves, Yu-Tsun Shao, Eric Parsonnet, Eric J. Marksz, Sahar Saremi, Margaret McCarter, A Reynoso, Chris Long, Aaron Hagerstrom, D Meyers, V Ravi, B Prasad, H Zhou, Z Zhang, H Wen, F Gomez-Ortiz, P Garcia-Fernandez, J Bokor, J Iniguez, J Freeland, Nate Orloff, J Junquera, Long-Qing Chen, Sayeef Salahuddin, David A. Muller, L Martin, R. Ramesh

Abstract

Topological solitons such as magnetic skyrmions have drawn enormous attention as stable quasi- particle-like objects. The recent discovery of polar vortices and skyrmions in ferroelectric- oxide superlattices, exhibiting exotic physical phenomena, has opened up new vistas to explore topology, emergent phenomena, and approaches for manipulating such features with electric fields. , Using macroscopic dielectric measurements, coupled with direct scanning convergent- beam electron diffraction (SCBED) imaging of the local polarization and electric-field profiles at the atomic scale, theoretical phase-field simulations, and second-principles calculations, we demonstrate that polar skyrmions in (PbTiO3)n/(SrTiO3)n superlattices are distinguished by a sheath of negative permittivity at the periphery of each skyrmion. This enables a strong enhancement of the effective dielectric permittivity as compared to individual SrTiO3 and PbTiO3 layers. Moreover, the response of these topologically protected structures to electric field and temperature reveal a reversible phase transition from a topologically protected skyrmion state (with a topological charge of +1) to a trivial uniform ferroelectric state (topological charge of 0), accompanied by a large tunability of the dielectric permittivity. Pulsed-switching measurements show a time-dependent evolution and recovery of the skyrmion state (and the macroscopic dielectric response). The interrelationship between the topological and the dielectric properties presents a unique opportunity to simultaneously manipulate both of both of them by a single, and easily controlled, stimulus, the applied electric field.
Citation
Nature Materials

Keywords

polar, skyrmion, ferroelectric, negative, permittivity, thin films

Citation

Das, S. , Hong, Z. , Stoica, V. , Goncalves, M. , Shao, Y. , Parsonnet, E. , Marksz, E. , Saremi, S. , McCarter, M. , Reynoso, A. , Long, C. , Hagerstrom, A. , Meyers, D. , Ravi, V. , Prasad, B. , Zhou, H. , Zhang, Z. , Wen, H. , Gomez-Ortiz, F. , Garcia-Fernandez, P. , Bokor, J. , Iniguez, J. , Freeland, J. , Orloff, N. , Junquera, J. , Chen, L. , Salahuddin, S. , Muller, D. , Martin, L. and Ramesh, R. (2020), Local negative permittivity and topological-phase transition in polar skyrmions, Nature Materials, [online], https://doi.org/10.1038/s41563-020-00818-y (Accessed October 7, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created October 11, 2020, Updated October 12, 2021
Was this page helpful?