Evidence for large thermodynamic signatures of in-gap fermionic quasiparticle states in a Kondo insulator.

ABSTRACT: The mixed-valence compound YbB₁₂ 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 insulato

SUBMITTER: Yang Z 

PROVIDER: S-EPMC11393308 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature