In-plane optical spectral weight redistribution in the optimally doped Ba_(0.6)K_(0.4)Fe_2As_2 superconductor  

作　　者：许兵 戴耀民 肖宏 R. P. S. M. Lobo 邱祥冈 

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences [2]LPEM, ESPCI-ParisTech, CNRS, UPMC, 10 rue Vauquelin,F-75231 Paris Cedex 5, France

出　　处：《Chinese Physics B》2014年第8期516-520,共5页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China(Grant Nos.2012CB821403,2011CBA00107,and 2012CB921302);the National Natural Science Foundation of China(Grant Nos.11374345,11104335,and 91121004)

摘　　要：We performed detailed temperature-dependent optical measurements on optimally doped Ba0.6K0.4Fe2As2 single crystal, We examine the changes of the in-plane optical conductivity spectral weight in the normal state and the evolution of the superconducting condensate in the superconducting state. In the normal state, the low-frequency spectral weight shows a metallic response with an arctan （T） dependence, indicating a T-linear scattering rate behavior for the carriers. A high energy spectral weight transfer associated with the Hund＇s coupling occurs from the low frequencies below 4000 cm^-1 5000 cm^-1 to higher frequencies up to at least 104 cm^-1. Its temperature dependence analysis suggests that the Hund＇s coupling strength is continuously enhanced as the temperature is reduced. In the superconducting state, the FGT sum rule is conserved according to the spectral weight estimation within the conduction bands, only about 40% of the conduction bands participates in the superconducting condensate indicating that Ba0.6K0.4Fe2As2 is in dirty limit.We performed detailed temperature-dependent optical measurements on optimally doped Ba0.6K0.4Fe2As2 single crystal, We examine the changes of the in-plane optical conductivity spectral weight in the normal state and the evolution of the superconducting condensate in the superconducting state. In the normal state, the low-frequency spectral weight shows a metallic response with an arctan （T） dependence, indicating a T-linear scattering rate behavior for the carriers. A high energy spectral weight transfer associated with the Hund＇s coupling occurs from the low frequencies below 4000 cm^-1 5000 cm^-1 to higher frequencies up to at least 104 cm^-1. Its temperature dependence analysis suggests that the Hund＇s coupling strength is continuously enhanced as the temperature is reduced. In the superconducting state, the FGT sum rule is conserved according to the spectral weight estimation within the conduction bands, only about 40% of the conduction bands participates in the superconducting condensate indicating that Ba0.6K0.4Fe2As2 is in dirty limit.

关 键 词：iron-based superconductor infrared spectroscopy optical properties 

分 类 号：O511.3[一般工业技术—材料科学与工程]