Evidence for large thermodynamic signatures of in-gap fermionic quasiparticle states in a Kondo insulator
The mixed-valence compound YbB<sub>12</sub> displays paradoxical quantum oscillations in electrical resistivity and magnetic torque in a regime with a well-developed insulating charge gap and in the absence of an electronic Fermi surface. However, signatures of such unusual fermionic quasiparticles in other bulk thermodynamic observables have been missing. Here we report the observation of a series of sharp double-peak features in the specific heat as a function of the magnetic field. The measured Hall resistivity evolves smoothly across the field values at which the characteristic anomalies appear in the thermodynamic response and rules out the possibility of conventional electrons as their origin. Our observations of thermodynamic anomalies in a bulk three-dimensional electrical insulator provide the evidence for the presence of emergent dispersing fermionic excitations within the insulating bulk, which sets the stage for further investigation of electron fractionalization in other correlated mixed-valence compounds.
Authors
- F. Iga (ORCID: https://orcid.org/0000-0001-6912-8414)
- Toshihiro Nomura (ORCID: https://orcid.org/0000-0002-7883-2072)
- Yoshimitsu Kohama (ORCID: https://orcid.org/0000-0003-0149-704X)
- Shusaku Imajo (ORCID: https://orcid.org/0000-0001-9870-3596)
- Albin De Muer
- Motoi Kimata (ORCID: https://orcid.org/0000-0003-4936-2988)
- Sunghoon Kim (ORCID: https://orcid.org/0000-0003-4936-9557)
- T. Klein (ORCID: https://orcid.org/0009-0007-7869-2296)
- Debanjan Chowdhury (ORCID: https://orcid.org/0000-0003-0758-0282)
- C. Marcenat (ORCID: https://orcid.org/0000-0002-5401-3240)
- Zhuo Yang (ORCID: https://orcid.org/0000-0002-6656-2239)
- D. K. Maude
Institutions
- École Nationale de l’Aviation Civile (FR)
- Centre National de la Recherche Scientifique (FR)
- Shizuoka University (JP)
- Université Toulouse III - Paul Sabatier (FR)
- Institut Superieur de l'Aeronautique et de l'Espace (ISAE-SUPAERO) (FR)
- Institut National des Sciences Appliquées de Toulouse (FR)
- Tohoku University (JP)
- Cornell University (US)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Office National d'Études et de Recherches Aérospatiales (FR)
- CEA Grenoble (FR)
- Laboratoire National des Champs Magnétiques Intenses (FR)
- Institut Néel (FR)
- Ibaraki University (JP)
- Hitachi (Japan) (JP)
- The University of Tokyo (JP)
- Institut de Mathématiques de Toulouse (FR)
- Université Grenoble Alpes (FR)
Publication Details
- Journal
- Nature Communications
- Published
- 2024-09-12
- DOI
- https://doi.org/10.1038/s41467-024-52017-x
- Citations
- 2
- Primary Topic
- Rare-earth and actinide compounds
- Type
- article
- Field-Weighted Citation Impact
- 0.62
Funders
- National Science Foundation
- Precise Measurement Technology Promotion Foundation
- Tsinghua University
- Centre National de la Recherche Scientifique
- Japan Society for the Promotion of Science
- Institute for Materials Research, Tohoku University
- Division of Materials Research