Ultrafast terahertz-field-driven ionic response in ferroelectric BaTiO[subscript 3]
Name
PhysRevB.94.180104.pdf
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Checksum (MD5)
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Author(s)
Chen, F.
Zhu, Y.
Liu, S.
Qi, Y.
Quirin, F.
Enquist, H.
Zalden, P.
Hu, T.
Goodfellow, J.
Sher, M.-J.
Alternative Title
Ultrafast terahertz-field-driven ionic response in ferroelectric BaTiO3
Date Issued
November 2016
Journal
Physical Review B
Publisher
American Physical Society
Citation
Chen, F. et al. “Ultrafast Terahertz-Field-Driven Ionic Response in Ferroelectric BaTiO 3.” Physical Review B 94.18 (2016): n. pag. © 2016 American Physical Society
Version
Final published version
Abstract
The dynamical processes associated with electric field manipulation of the polarization in a ferroelectric remain largely unknown but fundamentally determine the speed and functionality of ferroelectric materials and devices. Here we apply subpicosecond duration, single-cycle terahertz pulses as an ultrafast electric field bias to prototypical BaTiO[subscript 3] ferroelectric thin films with the atomic-scale response probed by femtosecond x-ray-scattering techniques. We show that electric fields applied perpendicular to the ferroelectric polarization drive large-amplitude displacements of the titanium atoms along the ferroelectric polarization axis, comparable to that of the built-in displacements associated with the intrinsic polarization and incoherent across unit cells. This effect is associated with a dynamic rotation of the ferroelectric polarization switching on and then off on picosecond time scales. These transient polarization modulations are followed by long-lived vibrational heating effects driven by resonant excitation of the ferroelectric soft mode, as reflected in changes in the c-axis tetragonality. The ultrafast structural characterization described here enables a direct comparison with first-principles-based molecular-dynamics simulations, with good agreement obtained.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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DOI of Published Version
https://doi.org/10.1103/PhysRevB.94.180104
