Abstract
In the iron-based superconductors, unconventional superconductivity emerges in proximity to intertwined electronic orders consisting of an electronic nematic order and a spin density wave (SDW). Recently, BaNi2As2, like its well-known iron-based analog BaFe2As2, has been discovered to host a symmetry-breaking structural transition but coupled to a unidirectional charge density wave (CDW) instead of SDW, providing a novel platform to study intertwined orders. Here, through a systematic angle-resolved photoemission spectroscopy study combined with a detwinning B1g uniaxial strain, we identify distinct spectral evidence of band evolution due to the structural transition as well as CDW-induced band folding. In contrast to the nematicity and spin density wave in BaFe2As2, the structural and CDW order parameters in BaNi2As2 are observed to be strongly coupled and do not separate in the presence of uniaxial strain. Furthermore, no nematic band splitting is resolved above the structural transition. Our measurements point to a likely lattice origin of the CDW order in BaNi2As2.
Original language | English |
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Article number | L081104 |
Journal | Physical Review B |
Volume | 108 |
Issue number | 8 |
DOIs | |
State | Published - Aug 15 2023 |
Funding
ARPES experiments were performed at the Advanced Light Source and the Stanford Synchrotron Radiation Lightsource, which are both operated by the Office of Basic Energy Sciences, U.S. DOE. Part of the research described in this work was also performed at the Canadian Light Source, a national research facility of the University of Saskatchewan, which is supported by Canada Foundation for Innovation (CFI), the Natural Sciences and Engineering Research Council of Canada (NSERC), the National Research Council (NRC), the Canadian Institutes of Health Research (CIHR), the Government of Saskatchewan, and the University of Saskatchewan. The ARPES work at Rice University was supported by the Robert A. Welch Foundation, Grant No. C-2024, and the Gordon and Betty Moore Foundation's EPiQS Initiative through Grant No. GBMF9470. The materials synthesis efforts at Rice are supported by the U.S. Department of Energy (DOE), Basic Energy Sciences (BES), under Contract No. DE-SC0012311, and the Robert A. Welch Foundation, Grant No. C-1839 (P.D.). Theory work at the University of Missouri was supported by the U.S. DOE, BES, Award No. DE-SC0019114. Work at the University of California, Berkeley, and Lawrence Berkeley National Laboratory was funded by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract No. DE-AC02-05CH11231 (Quantum Materials Program KC2202). This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231. Y.G. was supported in part by an ALS Doctoral Fellowship in Residence. The work at Oak Ridge National Laboratory was supported by the U.S. DOE, Office of Science, National Quantum Information Science Research Centers, and Quantum Science Center. This research was undertaken thanks, in part, to funding from the Max Planck–UBC–UTokyo Center for Quantum Materials and the Canada First Research Excellence Fund, Quantum Materials and Future Technologies Program.