AI 中文总结
本研究利用超快泵浦-探测显微术证实单个高振幅红外脉冲可通过瞬态应变驱动铁弹畴切换，为红外光调控铁性序提供了晶格介导的通用路径。
AI 中文摘要
晶格是凝聚态物质基本性质的基础，铁性序对原子配位高度敏感，因此调控晶格有望成为切换铁性材料状态的直接途径。红外激发为驱动晶格运动、产生瞬态晶体形变及应变提供了高效路径，铁弹体是实现这类调控的独特直接平台，其序参量本身就是应变。然而，超快激光诱导的晶格畸变能否切换铁弹序仍未知。本研究利用超快泵浦-探测显微术证实，单个高振幅红外脉冲在首个纳秒内诱导应变，随后数纳秒后发生铁弹畴切换；畴的空间分布符合光致应变场的预期，时间演化与应变动力学紧密耦合。研究结果确定瞬态应变为铁弹切换的驱动场，为用红外光调控铁性序提供了通用的晶格介导路径。
英文摘要
The crystal lattice underpins the fundamental properties of condensed matter, with ferroic order emerging sensitively from atomic coordination. Manipulating the lattic therefore promises a direct way to switch ferroics between their states. Infrared excitation provides an efficient pathway to drive lattice motion and generate transient crystal deformations and strains. Ferroelastics constitute a uniquely direct platform for such control, their order parameter being strain itself. However, whether ultrafast laser-induced lattice distortions can switch ferroelastic order remains unknown. Here we use ultrafast pump-probe microscopy to demonstrate that a single high-amplitude infrared pulse induces strain within the first nanosecond, followed by ferroelastic domain switching several nanoseconds later. The spatial distribution follows that expected from the photoinduced strain field, while their temporal evolution is closely coupled to the strain dynamics. Our observations identify transient strain as the driving field for ferroelastic switching and suggest a general lattice-mediated pathway for controlling ferroic order using infrared light.
