Year: 2025
Type: article
Abstract: Unraveling collective modes arising from coupled degrees of freedom is crucial for understanding complex interactions in solids and developing new functionalities. Unique collective behaviors emerge when two degrees of freedom, ordered on distinct length scales, interact. Polar skyrmions, three-dimensional electric polarization textures in ferroelectric superlattices, disrupt the lattice continuity at the nanometer scale with nontrivial topology, leading to previously unexplored collective modes. Here, using terahertz-field excitation and femtosecond x-ray diffraction, we discover subterahertz collective modes, dubbed "skyrons", which appear as swirling patterns of atomic displacements functioning as atomic-scale gearsets. The key to activating skyrons is the use of the THz field that couples primarily to skyrmion domain walls. Momentum-resolved time-domain measurements of diffuse scattering reveal an avoided crossing in the dispersion relation of skyrons. Atomistic simulations and dynamical phase-field modeling provide microscopic insights into the three-dimensional crystallographic and polarization dynamics. The amplitude and dispersion of skyrons are demonstrated to be controlled by sample temperature and electric-field bias. The discovery of skyrons and their coupling with terahertz fields opens avenues for ultrafast control of topological polar structures.
Source: Nature Communications
Authors: Huaiyu Hugo Wang, Vladimir A. Stoica, Cheng Dai, Marek Paściak, Sujit Das, Tiannan Yang, Mauro A. P. Gonçalves, Jiri Kulda, Margaret R. McCarter, Anudeep Mangu, Yue Cao, Hari Padma, Utkarsh Saha, Diling Zhu, Takahiro Sato, Sanghoon Song, Matthias C. Hoffmann, Patrick Kramer, Silke Nelson, Yanwen Sun, Quynh Nguyen, Zhan Zhang, Ramamoorthy Ramesh, Lane W. Martin, Aaron M. Lindenberg, Long-Qing Chen, John W. Freeland, Jirka Hlinka, Venkatraman Gopalan, Haidan Wen
Institutions: Pennsylvania State University, SLAC National Accelerator Laboratory, Argonne National Laboratory, Advanced Photon Source, FZU - Institute of Physics of the Czech Academy of Sciences, Indian Institute of Science Bangalore, Shanghai Jiao Tong University, Institut Laue-Langevin, University of California, Berkeley, Stanford University, Linac Coherent Light Source, Lawrence Berkeley National Laboratory, Rice University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: U.S. Department of Defense, U.S. Department of Energy, Indian Institute of Science, European Commission, Grantová Agentura České Republiky, Ministry of Education, India, Office of Science, Multidisciplinary University Research Initiative, Science and Engineering Research Board, Basic Energy Sciences, Army Research Office, Argonne National Laboratory, SLAC National Accelerator Laboratory
Awards: G102163711, G107546177, G1286236842, G1286251239, G1292847278, G1313983767, G1314494723, G1451874870, G1664757510, G1807881991, G2287611682, G2371548206, G2618837358, G262962599, G2638771445, G2677629327, G2678520069, G30714459, G3075337988, G3083819904, G3257681466, DYNAMIC VISUALIZATION AND CONTROL OF EMERGENT PHASES IN COMPLEX OXIDE HETEROSTRUCTURES, G3810236772, G415683661, G4185807686, G419881185, G426311843, G4269941704, G42916606, G4396925471, G4501827968, COMPUTATIONAL MESOSCALE SCIENCE AND OPEN SOFTWARE FOR QUANTUM MATERIALS, G498139845, G526230902, G5387317844, EMERGENT TOPOLOGICAL AND HIERARCHICAL ORDERED STRUCTURES (ETHOS), G6165425573, G6256534168, G650090426, G6550344761, G6652958823, G6848031779, G6918803902, G7382995341, G7452299184, G7583137537, G8227998441, G8382000481, COMPUTATIONAL MESOSCALE SCIENCE AND OPEN SOFTWARE FOR QUANTUM MATERIALS, G881401328, Ferroelectric skyrmions, G941802975, G969889393, G993149817
OpenAlex ID: W4414984750