Intrinsic Bulk Quantum Oscillations in a Bulk Unconventional Insulator SmB(6)

The finding of bulk quantum oscillations in the Kondo insulator SmB(6) proved a considerable surprise. Subsequent measurements of bulk quantum oscillations in other correlated insulators including YbB(12) lent support to our discovery of a class of bulk unconventional insulators that host bulk quantum oscillations. Here we perform a series of experiments to examine evidence for the intrinsic character of bulk quantum oscillations in floating zone-grown single crystals of SmB(6) that have been the subject of our quantum oscillation studies. We present results of thermodynamic, transport, and composition analysis experiments on pristine floating zone-grown single crystals of SmB(6) and compare quantum oscillations with metallic LaB(6) and elemental aluminum. These results establish the intrinsic origin of quantum oscillations from the insulating bulk of floating zone-grown SmB(6). The similarity of the Fermi surface in insulating SmB(6) with the conduction-electron Fermi surface in metallic hexaborides is at the heart of a theoretical mystery.