中国物理B ›› 2017, Vol. 26 ›› Issue (7): 77402-077402.doi: 10.1088/1674-1056/26/7/077402

所属专题: Virtual Special Topic — High temperature superconductivity

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Electronic structure and nematic phase transition in superconducting multiple-layer FeSe films grown by pulsed laser deposition method

Bing Shen(沈兵), Zhong-Pei Feng(冯中沛), Jian-Wei Huang(黄建伟), Yong Hu(胡勇), Qiang Gao(高强), Cong Li(李聪), Yu Xu(徐煜), Guo-Dong Liu(刘国东), Li Yu(俞理), Lin Zhao(赵林), Kui Jin(金魁), X J Zhou(周兴江)   

  1. 1 National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
  • 收稿日期:2017-05-23 修回日期:2017-05-25 出版日期:2017-07-05 发布日期:2017-07-05
  • 通讯作者: Lin Zhao, Kui Jin, X J Zhou E-mail:LZhao@iphy.ac.cn;kuijin@iphy.ac.cn;XJZhou@aphy.iphy.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No.11574360),the National Basic Research Program of China (Grant Nos.2015CB921300,2013CB921700,and 2013CB921904),the National Key Research and Development Program of China (Grant No.2016YFA0300300),and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No.XDB07020300).

Electronic structure and nematic phase transition in superconducting multiple-layer FeSe films grown by pulsed laser deposition method

Bing Shen(沈兵)1,2, Zhong-Pei Feng(冯中沛)1,2, Jian-Wei Huang(黄建伟)1,2, Yong Hu(胡勇)1,2, Qiang Gao(高强)1,2, Cong Li(李聪)1,2, Yu Xu(徐煜)1,2, Guo-Dong Liu(刘国东)1, Li Yu(俞理)1, Lin Zhao(赵林)1, Kui Jin(金魁)1, X J Zhou(周兴江)1,2,3   

  1. 1 National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
  • Received:2017-05-23 Revised:2017-05-25 Online:2017-07-05 Published:2017-07-05
  • Contact: Lin Zhao, Kui Jin, X J Zhou E-mail:LZhao@iphy.ac.cn;kuijin@iphy.ac.cn;XJZhou@aphy.iphy.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No.11574360),the National Basic Research Program of China (Grant Nos.2015CB921300,2013CB921700,and 2013CB921904),the National Key Research and Development Program of China (Grant No.2016YFA0300300),and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No.XDB07020300).

摘要:

We report comprehensive angle-resolved photoemission investigations on the electronic structure of single crystal multiple-layer FeSe films grown on CaF2 substrate by pulsed laser deposition (PLD) method. Measurements on FeSe/CaF2 samples with different superconducting transition temperatures Tc of 4 K, 9 K, and 14 K reveal electronic difference in their Fermi surface and band structure. Indication of the nematic phase transition is observed from temperature-dependent measurements of these samples; the nematic transition temperature is 140–160 K, much higher than~90 K for the bulk FeSe. Potassium deposition is applied onto the surface of these samples; the nematic phase is suppressed by potassium deposition which introduces electrons to these FeSe films and causes a pronounced electronic structure change. We compared and discussed the electronic structure and superconductivity of the FeSe/CaF2 films by PLD method with the FeSe/SrTiO3 films by molecular beam epitaxy (MBE) method and bulk FeSe. The PLD-grown multilayer FeSe/CaF2 is more hole-doped than that in MBE-grown multiple-layer FeSe films. Our results on FeSe/CaF2 films by PLD method establish a link between bulk FeSe single crystal and FeSe/SrTiO3 films by MBE method, and provide important information to understand superconductivity in FeSe-related systems.

关键词: iron-based superconductor, FeSe film, ARPES, electronic structure

Abstract:

We report comprehensive angle-resolved photoemission investigations on the electronic structure of single crystal multiple-layer FeSe films grown on CaF2 substrate by pulsed laser deposition (PLD) method. Measurements on FeSe/CaF2 samples with different superconducting transition temperatures Tc of 4 K, 9 K, and 14 K reveal electronic difference in their Fermi surface and band structure. Indication of the nematic phase transition is observed from temperature-dependent measurements of these samples; the nematic transition temperature is 140–160 K, much higher than~90 K for the bulk FeSe. Potassium deposition is applied onto the surface of these samples; the nematic phase is suppressed by potassium deposition which introduces electrons to these FeSe films and causes a pronounced electronic structure change. We compared and discussed the electronic structure and superconductivity of the FeSe/CaF2 films by PLD method with the FeSe/SrTiO3 films by molecular beam epitaxy (MBE) method and bulk FeSe. The PLD-grown multilayer FeSe/CaF2 is more hole-doped than that in MBE-grown multiple-layer FeSe films. Our results on FeSe/CaF2 films by PLD method establish a link between bulk FeSe single crystal and FeSe/SrTiO3 films by MBE method, and provide important information to understand superconductivity in FeSe-related systems.

Key words: iron-based superconductor, FeSe film, ARPES, electronic structure

中图分类号:  (Superconducting materials other than cuprates)

  • 74.70.-b
74.78.-w (Superconducting films and low-dimensional structures) 79.60.-i (Photoemission and photoelectron spectra) 74.25.Jb (Electronic structure (photoemission, etc.))