发表机构
Chongqing University; Peking University; Chongqing University of Arts and Sciences; Max Planck Institute for Chemical Physics of Solids; Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area; Center for High Pressure Science and Technology Advanced Research; Beijing Academy of Quantum Information Sciences; Tsung-Dao Lee Institute, School of Physics and Astronomy, Shanghai Jiao Tong University（重庆大学; 北京大学; 重庆文理学院; 马克斯·普朗克固体化学物理研究所; 粤港澳大湾区量子科学中心; 高压科学与技术前沿研究中心; 北京量子信息科学研究院; 上海交通大学物理与天文学院镛沙杜利研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过超快光谱研究EuAl4电荷密度波材料，发现光泵浦使带隙缩小并调制带间跃迁，建立了低能有序参量动力学与高能光谱响应的直接联系。
AI 中文摘要
超快泵浦-探测光谱是研究超导体和关联电子系统中相互作用、集体激发和非平衡动力学不可或缺的工具。然而，费米面附近的小带隙开启如何影响高能带间跃迁区域的光谱变化仍不清楚。为解决这一问题，我们对原型电荷密度波（CDW）材料EuAl4进行了载流子弛豫动力学的系统研究。我们发现，在光泵浦下，CDW带隙显著缩小。这种能带重整化强烈调制与带隙边缘相关的带间跃迁，在相应的探测能量处诱导出明显的瞬态反射率变化。这些结果建立了低能有序参量动力学与高能光谱响应之间的直接联系，为解释带隙量子材料中的瞬态信号提供了通用框架。
英文摘要
Ultrafast pump-probe spectroscopy is indispensable for investigating interactions, collective excitations, and nonequilibrium dynamics in superconductors and correlated electron systems. However, how a small gap opening near Fermi surface affects the spectral changes in the high-energy interband transition region remains elusive. To address this issue, we perform systematic studies of carrier relaxation dynamics in the prototype charge-density-wave (CDW) material EuAl4. We find that the CDW gap shrinks substantially under optical pumping. This band renormalization strongly modulates interband transitions associated with the gap edge, inducing a pronounced transient reflectivity change at the corresponding probe energies. These results establish a direct link between low-energy order-parameter dynamics and high-energy spectral responses, providing a general framework for interpreting transient signals in gapped quantum materials.
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