Lifshitz transitions in Kondo Insulator YbB₁₂

The Landau Level quantizations were observed in both magnetization and electrical resistivity in Kondo insulator YbB₁₂ [1,2]. At the intense magnetic fields, the quantum oscillation patterns resemble that contributions from the crystal bulk [3]. In contrast, at zero-field, the electrical conductance of the micron-size YbB₁₂ is shown to be independent of the sample thickness and thus indicating the origin of the surfaces [4]. To solve this problem, we carried out the Hall effect and Seebeck effect measurements in YbB₁₂ under intense magnetic fields. Our results suggest the magnetic field drives  Lifshitz transitions, which lead to the changes in electronic structures at the intense magnetic fields.