Kondo insulators in high magnetic fields*

Applied magnetic fields are a key tuning parameter in the study of Kondo insulators. In this talk, I will first discuss high-field magnetometry and electrical transport measurements of two Kondo insulators: SmB₆ and Ce₃Bi₄Pd₃. In the former, dHvA quantum oscillations from light effective masses vanish as embedded aluminum impurities are removed [1], and scanning tunneling microscopy reveals surface states with heavy effective masses. In the latter, a Fermi-liquid state emerges at remarkably low fields due to the closure of a modest Kondo gap [3]. I will then present recent electrical transport experiments in microstructured devices that show an enhancement of the modest Kondo gap of Ce₃Bi₄Pd₃ under hydrostatic pressure, a behavior typical of Kondo insulators [4]. At the end of the talk, I will highlight broader open questions in the field of Kondo insulators.