  In an exciting development, SmB6, a Kondo insulator has been shown to exhibit
bulk quantum oscillations. We propose that SmB6 is a bulk scalar Majorana Fermi
Liquid} (MFL) with a finite gap for charge and spin excitations. In their study
of Kondo insulators in 1993, Coleman, Miranda and Tsvelik (CMT) envisaged such
a remarkable possibility, using a mean field ansatz. We generalize CMT theory
to non-zero magnetic fields and show a counter intuitive result that the scalar
Majorana fermi liquid, while remaining electrically insulating, responds to
external magnetic field and exhibits Landau diamagnetism and quantum
oscillations. Physics of an emergent compactified 2-channel Kondo lattice
physics that is behind formation of the novel scalar Majorana fermi liquid
phase is discussed. It is also suggested that a known resistivity saturation in
SmB6 as well as a new strong deviation of quantum oscillation amplitude from
Lifshitz-Kosevich formula in SmB6 at low temperatures are due to a coherent
fluctuation of charge of a neutral scalar Majorana fermion. Possible presence
of 2-dimensional Majorana fermion excitations in surfaces of SmB6, and other
Topological Kondo Insulators (TKI) is pointed out.
