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arXiv · 1703.08962

Entropy spikes as a signature of Lifshitz transitions in the Dirac materials

V. Yu. Tsaran·A. V. Kavokin·S. G. Sharapov·A. A. Varlamov·V. P. Gusynin
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Abstract

We demonstrate theoretically that the characteristic feature of a 2D system undergoing $N$ consequent Lifshitz topological transitions is the occurrence of spikes of entropy per particle $s$ of a magnitude $\pm \ln 2/(J-1/2)$ with $2 \leq J \leq N$ at low temperatures. We derive a general expression for $s$ as a function of chemical potential, temperature and gap magnitude for the gapped Dirac materials. Inside the smallest gap, the dependence of $s$ on the chemical potential exhibits a dip-and-peak structure in the temperature vicinity of the Dirac point. The spikes of the entropy per particles can be considered as a signature of the Dirac materials. These distinctive characteristics of gapped Dirac materials can be detected in transport experiments where the temperature is modulated in gated structures.

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V. Yu. Tsaran, A. V. Kavokin, S. G. Sharapov, A. A. Varlamov, V. P. Gusynin. 2017-03-27. Entropy spikes as a signature of Lifshitz transitions in the Dirac materials. https://doi.org/10.1038/s41598-017-10643-0

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