发表机构
Stanford University; SLAC National Accelerator Laboratory; Shanghai Jiao Tong University（斯坦福大学; SLAC国家加速器实验室; 上海交通大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过原位拉伸应变选择性调控多铁性BiFeO3中与铁电和磁有序相关的光致晶格动力学，发现应变显著抑制铁电位移的超快减小，但对氧八面体旋转动力学不敏感，为关联材料超快相控制提供了新途径。
AI 中文摘要
量子材料的特征是相互交织的有序性，凝聚态物理的一个基本目标是以这样一种方式实现它们的选择性控制，即可以调控一个序参量而让其他序参量基本不受影响。尽管在热平衡方面已经取得了显著进展，但在非平衡状态下实现这种控制仍然极具挑战性。在此，我们利用原位拉伸应变来选择性地调控多铁性 BiFeO$_3$ 中与铁电和磁有序相关的光致晶格动力学。通过对可调应变下的自支撑 BiFeO$_3$ 薄膜应用 MeV 超快电子衍射，我们表明拉伸应变显著抑制了铁电位移的超快光致减小。相比之下，调节磁有序的氧八面体反铁畸变旋转的光致动力学对应变不敏感。这些发现不仅揭示了非平衡多铁动力学背后不同的微观路径，还确立了可调应变作为在关联材料中工程化超快相控制的有效途径。
英文摘要
Quantum materials are characterized by intertwined orders, and a fundamental goal in condensed matter physics is to achieve their selective control in such a way that one order parameter can be tuned while leaving others largely unaffected. Although significant progress has been made in thermal equilibrium, realizing such control out of equilibrium remains highly challenging. Here we employed in-situ tensile strain to selectively manipulate the photoinduced lattice dynamics associated with ferroelectric and magnetic orders in multiferroic BiFeO$_3$. By applying MeV ultrafast electron diffraction to freestanding BiFeO$_3$ membranes under tunable strain, we showed that tensile strain markedly suppresses the ultrafast photoinduced reduction of the ferroelectric displacement. By contrast, the photoinduced dynamics of the antiferrodistortive rotation of the oxygen octahedra, which modulates the magnetic order, remains insensitive to strain. Not only do these findings reveal distinct microscopic pathways underlying nonequilibrium multiferroic dynamics, they also establish tunable strain as an effective route for engineering ultrafast phase control in correlated materials.
Comments15 pages, 4 main figures and 8 Supplemental Material figures
