DOE OSTI · 3001465
Nodal hybridization in a two-dimensional heavy-fermion material
Abstract
Metals with partially filled core atomic shells can form quasiparticles at a low temperature arising from the hybridization of the core level and conduction electrons. The thermodynamic and spectroscopic properties of these metals can be understood as those of a simple metal, but with a significant mass enhancement over the free electron mass—commonly referred to as heavy fermions. In most heavy-fermion materials, the hybridization is approximately isotropic in position and momentum space. However, a combination of low dimensionality and symmetry properties of the core-level wavefunctions can give rise to highly anisotropic electronic interactions with the conduction electrons. Here, in this study, we demonstrate anisotropic hybridization that vanishes along specific directions in momentum space—referred to as nodes—in a lanthanide-based two-dimensional van der Waals heavy-fermion compound, CeSiI. Quasiparticle interference measurements reveal a set of discrete hotspots with high spectral intensity on the Fermi surface. Theoretical modelling and comparison with the quasiparticle interference pattern of the non-heavy-fermion isostructural analogue LaSiI suggest that these features arise from an unconventional electron interaction involving hybridization nodes unique to CeSiI. As a result, the effective mass of the quasiparticles varies by orders of magnitude depending on their direction in momentum space.
Explore related subjects
Keep this discovery
Explore connections, maps & timelines
Turkel, Simon [Columbia Univ., New York, NY (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000250117579), Posey, Victoria A. [Columbia Univ., New York, NY (United States)], Ong, Chin Shen [Uppsala Univ. (Sweden)] (ORCID:0000000187471849), Ghosh, Sanat [Columbia Univ., New York, NY (United States)], Huang, Xiong [Columbia Univ., New York, NY (United States)] (ORCID:0000000320358387), Kundu, Asish K. [Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000321991053), Vescovo, Elio [Brookhaven National Laboratory (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)] (ORCID:0000000303503861), Chica, Daniel G. [Columbia Univ., New York, NY (United States)], Thunström, Patrik [Uppsala Univ. (Sweden)] (ORCID:0000000285893930), Eriksson, Olle [Uppsala Univ. (Sweden)] (ORCID:0000000151111374), Simeth, Wolfgang [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000198901816), Scheie, Allen [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000274505138), Rubio, Angel [Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany); Univ. del País Vasco (UPV/EHU), San Sebastián (Spain); Flatiron Institute, New York, NY (United States)] (ORCID:0000000320603151), Millis, Andrew J. [Columbia Univ., New York, NY (United States); Flatiron Institute, New York, NY (United States)] (ORCID:0000000194136344), Roy, Xavier [Columbia Univ., New York, NY (United States)] (ORCID:0000000288500725), Pasupathy, Abhay N. [Columbia Univ., New York, NY (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000227440634). 2025-10-14. Nodal hybridization in a two-dimensional heavy-fermion material. https://doi.org/10.1038/s41567-025-03060-y
Cite the original work for its findings. Save a collection to share your selection of sources.