Electronic Structure Reconstruction across the Antiferromagnetic Transition in TaFe1.23Te3 Spin Ladder
XU Min1, WANG Li-Min2, PENG Rui1,7, GE Qing-Qin1, CHEN Fei1, YE Zi-Rong1, ZHANG Yan1, CHEN Su-Di1, XIA Miao1, LIU Rong-Hua3, Arita M.4, Shimada K.4, Namatame H.4, Taniguchi M.4, Matsunami M.5, Kimura S.5, SHI Ming6, CHEN Xian-Hui3, YIN Wei-Guo2, KU Wei2**, XIE Bin-Ping1,7**, FENG Dong-Lai1,7**
1State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433 2Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, New York 11973, USA 3Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026 4Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-8526, Japan 5UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan 6Swiss Light Source, Paul-Scherrer Institute, Villigen 5232, Switzerland 7Collaborative Innovation Center of Advanced Microstructures, 22 Hankou Road, Gulou, Nanjing 210093
Employing the angle-resolved photoemission spectroscopy, we study the electronic structure of TaFe1.23Te3, a two-leg spin ladder compound with a novel antiferromagnetic ground state. Quasi-two-dimensional (2D) Fermi surface is observed, with sizable inter-ladder hopping. Moreover, instead of observing an energy gap at the Fermi surface in the antiferromagnetic state, we observe the shifts of various bands. Combining these observations with density-functional-theory calculations, we propose that the large scale reconstruction of the electronic structure, caused by the interactions between the coexisting itinerant electrons and local moments, is most likely the driving force of the magnetic transition. Thus TaFe1.23Te3 serves as a simpler platform that contains similar ingredients to the parent compounds of iron-based superconductors.
2015, Vol. 32 
