Electronic structure and nematic phase transition in superconducting multiple-layer FeSe films grown by pulsed laser deposition method
Shen Bing1, 2, Feng Zhong-Pei1, 2, Huang Jian-Wei1, 2, Hu Yong1, 2, Gao Qiang1, 2, Li Cong1, 2, Xu Yu1, 2, Liu Guo-Dong1, Yu Li1, Zhao Lin1, †, Jin Kui1, ‡, Zhou X J1, 2, 3, §
       

Temperature dependence of the nematic phase transition in FeSe/CaF2 films. (a) and (b) show photoemission spectra (EDCs) measured at different temperatures at the momentum point k1 for the S4K and S14K samples, respectively. The dashed lines are guide to eyes for locating the peak positions. The location of the momentum point k1 is marked in (c) which shows the band structure of the S14K sample measured at 30 K along the momentum cut crossing M3 shown in Fig. 3(b). The k0 in (c) represents the M point. The two bands in (c) are fitted by parabolas. (d) shows the distance between the two hole-like bands in (c) at k1 and k0 points for the S4K, S9K, and S14K samples.