Subterahertz collective dynamics of polar vortices
The collective dynamics of topological structures 1 – 6 are of interest from both fundamental and applied perspectives. For example, studies of dynamical properties of magnetic vortices and skyrmions 3 , 4 have not only deepened our understanding of many-body physics but also offered potential appli...
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| Vydáno v: | Nature (London) Ročník 592; číslo 7854; s. 376 - 380 |
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| Hlavní autoři: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
London
Nature Publishing Group UK
15.04.2021
Nature Publishing Group |
| Témata: | |
| ISSN: | 0028-0836, 1476-4687, 1476-4687 |
| On-line přístup: | Získat plný text |
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| Shrnutí: | The collective dynamics of topological structures
1
–
6
are of interest from both fundamental and applied perspectives. For example, studies of dynamical properties of magnetic vortices and skyrmions
3
,
4
have not only deepened our understanding of many-body physics but also offered potential applications in data processing and storage
7
. Topological structures constructed from electrical polarization, rather than electron spin, have recently been realized in ferroelectric superlattices
5
,
6
, and these are promising for ultrafast electric-field control of topological orders. However, little is known about the dynamics underlying the functionality of such complex extended nanostructures. Here, using terahertz-field excitation and femtosecond X-ray diffraction measurements, we observe ultrafast collective polarization dynamics that are unique to polar vortices, with orders-of-magnitude higher frequencies and smaller lateral size than those of experimentally realized magnetic vortices
3
. A previously unseen tunable mode, hereafter referred to as a vortexon, emerges in the form of transient arrays of nanoscale circular patterns of atomic displacements, which reverse their vorticity on picosecond timescales. Its frequency is considerably reduced (softened) at a critical strain, indicating a condensation (freezing) of structural dynamics. We use first-principles-based atomistic calculations and phase-field modelling to reveal the microscopic atomic arrangements and corroborate the frequencies of the vortex modes. The discovery of subterahertz collective dynamics in polar vortices opens opportunities for electric-field-driven data processing in topological structures with ultrahigh speed and density.
A dynamical study shows that vortices of electrical polarization have higher frequencies and smaller size than their magnetic counterparts, properties that are promising for electric-field-driven data processing. |
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| Bibliografie: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 National Research Foundation of Korea (NRF) USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division SC0012375; FG02-04ER46147; AC02-05-15CH11231; AC02-06CH11357; AC02-76SF00515; SC0014664; 19-28594X; SC0020145; 2017R1A6A3A11030959; DMR-1720415; 51788104; DMR-1744213 USDOE Office of Science (SC), Basic Energy Sciences (BES) National Science Foundation (NSF) National Natural Science Foundation of China (NSFC) Czech Science Foundation |
| ISSN: | 0028-0836 1476-4687 1476-4687 |
| DOI: | 10.1038/s41586-021-03342-4 |