Observation of Quantum Oscillations in the Low Temperature Specific Heat of SmB₆

We report measurements of the low-temperature specific heat of Al-flux-grown samples of SmB₆ in magnetic fields up to 32T. Quantum oscillations periodic in 1/H are observed between 8 and 32 T at selected angles between [001] and [111]. The observed frequencies and their angular dependence are consistent with previous magnetic torque measurements of SmB₆ but the effective masses (inferred from Lifshitz-Kosevich theory) are significantly larger than those inferred from magnetic torque. The magnetic field dependence of the oscillation amplitude is inconsistent with that expected to arise from aluminum inclusions. Instead, our results suggest a bulk density of states origin for the quantum oscillations.