Quantitative evaluation of Dirac physics in PbTe

Exploration of novel macroscopic responses stemming from relativistic Dirac fermions in materials has become popular in condensed matter physics. Here, the authors carefully analyze the quantum oscillations in PbTe and evaluate the ratio of the Zeeman to the cyclotron energy, which has been proposed as a macroscopic index to find how close the system is to the ideal two-band Dirac system. The results remind us of the importance of the trivial phase shift by Zeeman splitting when considering the nontrivial Berry phase from quantum oscillations in topological materials.