2025-01-16 アルゴンヌ国立研究所
＜関連情報＞
- https://www.anl.gov/article/metastable-marvel-xrays-illuminate-an-exotic-material-transformation
- https://www.nature.com/articles/s41563-024-01981-2
極性超構造の出現への非平衡経路 Non-equilibrium pathways to emergent polar supertextures
Vladimir A. Stoica,Tiannan Yang,Sujit Das,Yue Cao,Huaiyu (Hugo) Wang,Yuya Kubota,Cheng Dai,Hari Padma,Yusuke Sato,Anudeep Mangu,Quynh L. Nguyen,Zhan Zhang,Disha Talreja,Marc E. Zajac,Donald A. Walko,Anthony D. DiChiara,Shigeki Owada,Kohei Miyanishi,Kenji Tamasaku,Takahiro Sato,James M. Glownia,Vincent Esposito,Silke Nelson,Matthias C. Hoffmann,… John W. Freeland
Nature Materials Published:24 September 2024
DOI:https://doi.org/10.1038/s41563-024-01981-2
Abstract
Ultrafast stimuli can stabilize metastable states of matter inaccessible by equilibrium means. Establishing the spatiotemporal link between ultrafast excitation and metastability is crucial to understand these phenomena. Here we utilize single-shot optical pump–X-ray probe measurements to capture snapshots of the emergence of a persistent polar vortex supercrystal in a heterostructure that hosts a fine balance between built-in electrostatic and elastic frustrations by design. By perturbing this balance with photoinduced charges, an initially heterogeneous mixture of polar phase disorders within a few picoseconds, leading to a state composed of disordered ferroelectric and suppressed vortex orders. On the picosecond–nanosecond timescales, transient labyrinthine fluctuations develop, accompanied by the recovery of the vortex order. On longer timescales, these fluctuations are progressively quenched by dynamical strain modulations, which drive the collective emergence of a single vortex supercrystal phase. Our results, corroborated by dynamical phase-field modelling, reveal non-equilibrium pathways following the ultrafast excitation of designer systems to persistent metastability.
