高温超导机理的光电子能谱和超快光谱研究

高温超导的微观起源一直是凝聚态物理的前沿课题。研究已经取得了很大进展，但远未完成。高温超导和异常正常态挑战着传统理论，如BCS理论和朗道费米液体理论。理解高温超导的微观机理，突破传统的朗道费米液体理论，建立强关联电子态和量子相变的新理论，是这个时代面临的重大科学问题之一，也是寻找和应用具有更高转变温度材料的需要，关系国家经济、社会、安全等战略需要。我们计划综合时间分辨/角分辨光电子能谱和超快光谱对高温超导机理和奇异正常态开展系统和深入的研究。我们将整合材料、实验、理论和超快控制理论的力量，研究与超导机理和奇异正常态密切相关的核心问题：在频域和时域辨认多体效应和参与配对的玻色子的本质；确认铁基超导体中是否存在窄的赝能隙，并研究其的本质；在时域精确测量声子频率随温度的演化，寻找可能的电荷密度波，并研究其与超导的关系。本项目的实施将为理解高温超导微观机理提供关键信息，推动新的成功的理论的建立。

Understanding the microscopic origin of high-temperature superconductivity is a frontier topic in condensed matter physics. Great progress has been made in this field, but it is far from successful. High-temperature superconductivity and abnormal normal state challenge traditional theories such as BCS theory and Landau Fermi liquid theory. Understanding the microscopic mechanism of high-temperature superconductivity, breaking through the traditional Landau Fermi liquid theory, and establishing a new theory of strongly correlated electronic states and quantum phase transition is not only one of the major scientific challenges faced in this era, but also the need to find and apply materials with higher superconducting transition temperature, which is related to the national strategic needs of economy, society, security and so on. We plan to use angle-resolved photoemission spectroscopy, time-resolved and angle-resolved photoemission spectroscopy, and ultrafast optical spectroscopy to carry out systematic and in-depth research on the mechanism of high-temperature superconductivity and the abnormal normal state. Combining the efforts of materials, experiments, theories and ultrafast control theory, we will focus on the central mysteries closely related to the superconducting mechanism and abnormal normal state: identifying the many-body effect and the nature of bosons involved in cooper pairs in the frequency domain and time domain; determining the existence of narrow pseudogaps in the iron-based superconductor, and studying the nature of pseudogaps; measuring the evolution of phonon frequency with temperature in the time domain, finding the possible charge density wave order, and studying its interplay with superconductivity. The implementation of this project will provide key information for understanding the microscopic mechanism of high-temperature superconductivity, and promote the establishment of new and successful theories.