Elastically driven cooperative response of a molecular material impacted by a laser pulse
Elastically driven cooperative response of a molecular material impacted by a laser pulse
复制标题
DOI：
10.1038/nmat4606
复制
发表时间：
2016-06-01
期刊：
影响因子：
41.2
通讯作者：
Collet, Eric
中科院分区：
文献类型：
--
作者：
Bertoni, Roman;Lorenc, Maciej;Collet, Eric
当激光脉冲撞击材料时，会发生光致相变 (1,2)，从而改变其电子和/或结构顺序，从而影响功能 (3-7)。迄今为止，光诱导态的瞬态性质严重限制了应用范围。探索固体变形过程中的结构反馈是否具有放大和稳定光致转变的能力至关重要。与长期以来受到审查的相干光学声子相反(8-10)，声学时间尺度上的相干传播细胞变形(11-14)尚未得到类似程度的探索，特别是在协作弹性相互作用方面。在这里，我们通过实验和理论上证明了自旋交叉材料（15）在延迟体积膨胀期间的自放大响应性。材料尺度上的协同响应普遍高于阈值激发，显着延长了光诱导态的寿命。这种由光脉冲触发的弹性驱动协同性为许多体积变化材料中光致相的生成和稳定提供了有效的途径。
Photoinduced phase transformations(1,2) occur when a laser pulse impacts a material, thereby transforming its electronic and/or structural orders, consequently affecting the functionalities(3-7). The transient nature of photoinduced states has thus far severely limited the scope of applications. It is of paramount importance to explore whether structural feedback during the solid deformation has the capacity to amplify and stabilize photoinduced transformations. Contrary to coherent optical phonons, which have long been under scrutiny(8-10), coherently propagating cell deformations over acoustic timescales(11-14) have not been explored to a similar degree, particularly with respect to cooperative elastic interactions. Herein we demonstrate, experimentally and theoretically, a self-amplified responsiveness in a spin-crossover material(15) during its delayed volume expansion. The cooperative response at the material scale prevails above a threshold excitation, significantly extending the lifetime of photoinduced states. Such elastically driven cooperativity triggered by a light pulse offers an efficient route towards the generation and stabilization of photoinduced phases in many volume-changing materials.