摘要
We report an in-depth investigation on the out-of-plane lower critical field Hc1 of the KCa2(Fe1-xCox)4As4F2(12442-type,x=0,0.1).The multi-gap feature is revealed by the kink in the temperature-dependent Hc1(T)curve for the two samples with different doping levels.Based on a simplified two-gap model,the magnitudes of the two gaps are determined to beΔ1=1.2 meV andΔ2=5.0 meV for the sample with x=0,Δ1=0.86 meV andΔ2=2.8 meV for that with x=0.1.With the cobalt doping,the ratio of energy gap to critical transition temperature(Δ/kBTc)remains almost unchanged for the smaller gap and is suppressed by 20%for the larger gap.For the undoped KCa2Fe4As4F2,the obtained gap sizes are generally consistent with the results of angle-resolved photoemission spectroscopy experiments.
作者
Jianan Chu
Teng Wang
Han Zhang
Yixin Liu
Jiaxin Feng
Zhuojun Li
Da Jiang
Gang Mu
Zengfeng Di
Xiaoming Xie
楚佳楠;王腾;张瀚;刘以鑫;冯嘉鑫;李卓君;姜达;牟刚;狄增峰;谢晓明(State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;CAS Center for Excellence in Superconducting Electronics(CENSE),Shanghai 200050,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China)
基金
the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2015187)
the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grant No.XDB30000000)
the National Natural Science Foundation of China(Grant Nos.11704395 and 11204338)。
