Fig. 1: Illustration for topological and Sommerfeld contributions to temperature dependence of oscillation frequency.
From: Temperature dependence of quantum oscillations from non-parabolic dispersions
a For a linearly dispersing Dirac-type pocket, the energy derivative of the cyclotron mass, \(\partial ({{{{{{\mathrm{log}}}}}}}\,{m}_{{{{{{\rm{c}}}}}}})/\partial E\) diverges when the Fermi level approaches the Dirac node. When approaching the Dirac node, the Fermi pocket shrinks and the cyclotron mass is continuously decreasing to zero, therefore the smaller the oscillation frequency, the larger the oscillation amplitude. Due to the thermal broadening of chemical potential, this ultimately leads to the quadratic temperature dependence of the quantum-oscillation frequency. In constrast, for a Schrödinger-type pocket with a parabolic dispersion, \(\partial ({{{{{{\mathrm{log}}}}}}}\,{m}_{c})/\partial E=0\). b Illustration of Sommerfeld contribution, describes the shift of chemical potential at finite temperatures due to thermal broadening with a fixed carrier density.
