Quantum Oscillations And Charge Neutral Fermions in Topological Kondo Insulator Ybb₁₂

Electronic state of every solid is basically classified into two categories according to its electrical responses: insulator or metal. A textbook of modern solid state physics explains that shape of a Fermi surface plays a key role in most physical properties in metals. One of the well-established experimental methods to detect a Fermi surface is measurement of quantum oscillations that is a periodic response of physical quantities with respect to external magnetic fields. As insulators do not host Fermi surface, it is believed that they do not exhibit any quantum oscillations.