FeAs基超导体的超快光谱研究

Ultrafast optical spectroscopy of FeAs-based superconductors

铁基超导体作为第二个被发现的高温超导体家族,其超导机理无疑是现代物理学中最引人注目的物理问题之一.从凝聚态的角度上看,铁基超导体丰富的有序态主要源于微观自由度,如电荷、轨道、自旋和晶格之间的相互作用演绎而来.近年来,随着飞秒激光技术的飞速发展,超快光谱成为了直接探测材料宏观物理量的微观机制及各种微观自由度之间相互作用的有力工具之一,并广泛应用于铁基超导体研究.本文回顾了FeAs基超导体最近的超快光谱研究,其中包括对能隙函数的探讨、在时域内区分各种有序相及这些相与超导序之间的关系以及相干声子在超导配对中的作用等方面的进展.

The mechanism of iron-based superconductors,which is the second discovered family of high-temperature superconductors,is one of the most attractive research hotspots in modern physics.From the condensed matter perspective,the abundant ordered states in iron-based superconductors originate from the interaction between the microscopic degrees of freedom of electron,lattice,spin,and orbit.Recently,the rapid development of femtosecond lasers has resulted in the emergence of ultrafast optical spectroscopy as a powerful tool for understanding the microscopic mechanism of various interesting phenomena in materials and the interaction between degrees of freedom and has been widely applied in high-temperature superconductor research.Herein,the most recent results on the application of ultrafast optical spectroscopy for studying FeAs-based superconductors are presented,including the gap function,identification of various orders in the time domain,interpretation of the relation between the ordered states and superconductivity,and role of coherent phonons in forming Cooper pairs.