Electronic correlations are crucial to the low-energy physics of metallic systems with localized and 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 ( ). Additionally, angle-resolved photoemission spectroscopy reveals a mass renormalization of , where is the measured effective mass and 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.
Shourov, Estiaque H., Strohbeen, Patrick J., Du, Dongxue, et al., "Electronic correlations in the semiconducting half-Heusler compound FeVSb," Physical Review. B 103, no. 4 (2021), https://doi.org/10.1103/physrevb.103.045134
@article{osti_1765372,
author = {Shourov, Estiaque H. and Strohbeen, Patrick J. and Du, Dongxue and Sharan, Abhishek and de Lima, Felipe C. and Rodolakis, Fanny and McChesney, Jessica L. and Yannello, Vincent and Janotti, Anderson and Birol, Turan and others},
title = {Electronic correlations in the semiconducting half-Heusler compound FeVSb},
annote = {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). Additionally, 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.},
doi = {10.1103/physrevb.103.045134},
url = {https://www.osti.gov/biblio/1765372},
journal = {Physical Review. B},
issn = {ISSN 2469-9950},
number = {4},
volume = {103},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2021},
month = {01}}
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE Office of Science (SC); University of Wisconsin - Madison - Materials Research Science and Engineering Center (MRSEC)