Visualization of the electronic phase separation in superconducting KxFe2-ySe2

被引:8
作者
Chen, Yujie [1 ]
Jiang, Juan [2 ,3 ]
Yang, Haifeng [4 ,5 ]
Dudin, Pavel [6 ]
Barinov, Alexey [7 ]
Liu, Zhongkai [4 ,5 ,8 ]
Wen, Haihu [9 ,10 ]
Yang, Lexian [1 ,11 ]
Chen, Yulin [1 ,2 ,4 ,5 ,8 ]
机构
[1] Tsinghua Univ, Dept Phys, State Key Lab Low Dimens Quantum Phys, Beijing 100084, Peoples R China
[2] Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England
[3] Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA
[4] ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 201210, Peoples R China
[5] CAS Shanghai Sci Res Ctr, Shanghai 201210, Peoples R China
[6] Synchrotron SOLEIL, Orme Merisiers, St Aubin BP 48, F-91192 Gif Sur Yvette, France
[7] Elettra Sincrotrone Trieste, I-34149 Trieste, Basovizza, Italy
[8] ShanghaiTech Lab Topol Phys, Shanghai 200031, Peoples R China
[9] Nanjing Univ, Natl Lab Solid State Microstruct, Nanjing 210093, Peoples R China
[10] Nanjing Univ, Dept Phys, Nanjing 210093, Peoples R China
[11] Frontier Sci Ctr Quantum Informat, Beijing 100084, Peoples R China
基金
英国工程与自然科学研究理事会; 国家重点研发计划; 中国国家自然科学基金;
关键词
spatial- and angle-resolved photoemission spectroscopy (mu-ARPES); iron-based superconductors; phase separation; electronic structure; CS;
D O I
10.1007/s12274-020-3119-8
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Type-II iron-based superconductors (Fe-SCs), the alkali-metal-intercalated iron selenide A(x)Fe(2-y)Se(2) (A = K, Tl, Rb, etc.) with a superconducting transition temperature of 32 K, exhibit unique properties such as high Neel temperature, Fe-vacancies ordering, antiferromagnetically ordered insulating state in the phase diagram, and mesoscopic phase separation in the superconducting materials. In particular, the electronic and structural phase separation in these systems has attracted intensive attention since it provides a platform to unveil the insulating parent phase of type-II Fe-SCs that mimics the Mott parent phase in cuprates. In this work, we use spatial- and angle-resolved photoemission spectroscopy to study the electronic structure of superconducting KxFe2-ySe2. We observe clear electronic phase separation of KxFe2-ySe2 into metallic islands and insulating matrix, showing different K and Fe concentrations. While the metallic islands show strongly dispersive bands near the Fermi level, the insulating phase shows an energy gap up to 700 meV and a nearly flat band around 700 meV below the Fermi energy, consistent with previous experimental and theoretical results on the superconducting K1-xFe2Se2 (122 phase) and Fe-vacancy ordered K0.8Fe1.6Se2 (245 phase), respectively. Our results not only provide important insights into the mysterious composition of phase-separated superconducting and insulating phases of KxFe2-ySe2, but also present their intrinsic electronic structures, which will shed light on the comprehension of the unique physics in type-II Fe-SCs.
引用
收藏
页码:823 / 828
页数:6
相关论文
共 37 条
[11]   Influence of microstructure on superconductivity in KxFe2 - ySe2 and evidence for a new parent phase K2Fe7Se8 [J].
Ding, Xiaxin ;
Fang, Delong ;
Wang, Zhenyu ;
Yang, Huan ;
Liu, Jianzhong ;
Deng, Qiang ;
Ma, Guobin ;
Meng, Chong ;
Hu, Yuhui ;
Wen, Hai-Hu .
NATURE COMMUNICATIONS, 2013, 4
[12]   Imaging the local electronic and magnetic properties of intrinsically phase separated Rbx(Fe2-ySe2 superconductor using scanning microscopy techniques [J].
Dudin, P. ;
Herriott, D. ;
Davies, T. ;
Krzton-Maziopa, A. ;
Pomjakushina, E. ;
Conder, K. ;
Cacho, C. ;
Yates, J. R. ;
Speller, S. C. .
SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 2019, 32 (04)
[13]   Fe-based superconductivity with Tc=31 K bordering an antiferromagnetic insulator in (Tl,K) FexSe2 [J].
Fang, Ming-Hu ;
Wang, Hang-Dong ;
Dong, Chi-Heng ;
Li, Zu-Juan ;
Feng, Chun-Mu ;
Chen, Jian ;
Yuan, H. Q. .
EPL, 2011, 94 (02)
[14]   Superconductivity in the iron selenide KxFe2Se2 (0 ≤x≤1.0) [J].
Guo, Jiangang ;
Jin, Shifeng ;
Wang, Gang ;
Wang, Shunchong ;
Zhu, Kaixing ;
Zhou, Tingting ;
He, Meng ;
Chen, Xiaolong .
PHYSICAL REVIEW B, 2010, 82 (18)
[15]   Superconductivity in alkali metal intercalated iron selenides [J].
Krzton-Maziopa, A. ;
Svitlyk, V. ;
Pomjakushina, E. ;
Puzniak, R. ;
Conder, K. .
JOURNAL OF PHYSICS-CONDENSED MATTER, 2016, 28 (29)
[16]   Phase separation in superconducting and antiferromagnetic Rb0.8Fe1.6Se2 probed by Mossbauer spectroscopy [J].
Ksenofontov, Vadim ;
Wortmann, Gerhard ;
Medvedev, Sergey A. ;
Tsurkan, Vladimir ;
Deisenhofer, Joachim ;
Loidl, Alois ;
Felser, Claudia .
PHYSICAL REVIEW B, 2011, 84 (18)
[17]   KFe2Se2 is the Parent Compound of K-Doped Iron Selenide Superconductors [J].
Li, Wei ;
Ding, Hao ;
Li, Zhi ;
Deng, Peng ;
Chang, Kai ;
He, Ke ;
Ji, Shuaihua ;
Wang, Lili ;
Ma, Xucun ;
Hu, Jiang-Ping ;
Chen, Xi ;
Xue, Qi-Kun .
PHYSICAL REVIEW LETTERS, 2012, 109 (05)
[18]  
Li W, 2012, NAT PHYS, V8, P126, DOI [10.1038/NPHYS2155, 10.1038/nphys2155]
[19]   Formation mechanism of superconducting phase and its three-dimensional architecture in pseudo-single-crystal KxFe2-ySe2 [J].
Liu, Yong ;
Xing, Qingfeng ;
Straszheim, Warren E. ;
Marshman, Jeff ;
Pedersen, Pal ;
McLaughlin, Richard ;
Lograsso, Thomas A. .
PHYSICAL REVIEW B, 2016, 93 (06)
[20]   Photoemission and muon spin relaxation spectroscopy of the iron-based Rb0.77Fe1.61Se2 superconductor: Crucial role of the cigar-shaped Fermi surface [J].
Maletz, J. ;
Zabolotnyy, V. B. ;
Evtushinsky, D. V. ;
Yaresko, A. N. ;
Kordyuk, A. A. ;
Shermadini, Z. ;
Luetkens, H. ;
Sedlak, K. ;
Khasanov, R. ;
Amato, A. ;
Krzton-Maziopa, A. ;
Conder, K. ;
Pomjakushina, E. ;
Klauss, H. -H. ;
Rienks, E. D. L. ;
Buechner, B. ;
Borisenko, S. V. .
PHYSICAL REVIEW B, 2013, 88 (13)