电荷密度波中的亚晶格分辨相干声子动力学
Sublattice-resolved coherent phonon dynamics in charge density waves
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中文总结 AI 辅助
本文针对电荷密度波材料EuTe4，利用时间分辨共振X射线散射提出动态方案，解析出三种不同亚晶格特征的相干声子模式，为多元素材料的相干声子分解提供了新框架。
中文摘要 AI 辅助
声子决定材料的基本性质，在多种电子相变中发挥核心作用。相干驱动特定声子模式可实现按需相控，因此需要对实空间声子运动进行亚晶格分辨识别，但实验上解析这些运动仍具挑战性，限制了基于声子的精准控制。本文提出一种动态方案，用于追踪电荷密度波材料EuTe4中元素分辨的声子动力学，该材料中主导的Te亚晶格电荷有序伴随此前未报道的Eu亚晶格分量。我们利用时间分辨共振X射线散射的元素选择性，揭示了三种具有不同亚晶格特征的相干声子模式，从而区分了Eu和Te主导的晶格动力学，与声子本征矢量的理论计算结果吻合良好。这种时域方法超越了传统频域非弹性散射的能量分辨率极限，为多元素材料中相干声子的分解提供了广泛适用的框架，这对物质相的靶向控制至关重要。
英文摘要
Phonons govern fundamental material properties and play a central role in various electronic phase transitions. Coherent driving of specific phonon modes enables on-demand phase control, motivating sublattice-resolved identification of real-space phonon motions. Yet experimentally resolving these motions remains challenging, limiting precise phonon-based control. Here, we introduce a dynamical protocol to track element-resolved phonon dynamics in the charge density wave material EuTe4, in which the dominant Te-sublattice charge order is accompanied by a previously unreported Eu-sublattice component. We leverage the elemental selectivity of time-resolved resonant X-ray scattering to reveal three coherent phonon modes with distinct sublattice character, thereby disentangling Eu- and Te-dominated lattice dynamics, in good agreement with theoretical calculations of the phonon eigenvectors. This time-domain approach, which surpasses the energy-resolution limits of conventional frequency-domain inelastic scattering, provides a broadly applicable framework for decomposing coherent phonons in multi-element materials, which is crucial for the targeted control of phases of matter.
