Abstract
Electronic correlations are crucial to the low-energy physics of metallic systems with localized d and f states; however, their effect on band insulators and semiconductors is typically negligible. Here, we measure the electronic structure of the half-Heusler compound FeVSb, a band insulator with a filled shell configuration of 18 valence electrons per formula unit (s2p6d10). Angle-resolved photoemission spectroscopy reveals a mass renormalization of m∗/mbare=1.4, where m∗ is the measured effective mass and mbare is the mass from density functional theory calculations with no added on-site Coulomb repulsion. Our measurements are in quantitative agreement with dynamical mean-field theory calculations, highlighting the many-body origin of the mass renormalization. This mass renormalization lies in dramatic contrast to other filled shell intermetallics, including the thermoelectric materials CoTiSb and NiTiSn, and has a similar origin to that in FeSi, where Hund's coupling induced fluctuations across the gap can explain a dynamical self-energy and correlations. Our work calls for a rethinking of the role of correlations and Hund's coupling in intermetallic band insulators.
Original language | English (US) |
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Article number | 045134 |
Journal | Physical Review B |
Volume | 103 |
Issue number | 4 |
DOIs | |
State | Published - Jan 25 2021 |
Bibliographical note
Funding Information:We thank J. Harter (UCSB) and K. Shen (Cornell) for the ARPES analysis tools. This work was supported by the CAREER program of the National Science Foundation (DMR-1752797) and the SEED program of the Wisconsin Materials Research Science and Engineering Center (DMR-1720415). This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357, with additional support by the National Science Foundation under Grant No. DMR-0703406. Work at the University of Minnesota was supported by the Department of Energy through the University of Minnesota Center for Quantum Materials under DE-SC-0016371. We acknowledge the Minnesota Supercomputing Institute for providing resources that contributed to the DMFT results reported within this paper. A.J. acknowledges support from the U.S. Department of Energy Basic Energy Science program Grant No. DE-SC0014388, and the NERSC supercomputing facility.
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