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

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 $2\le J\le N$ 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.

8 pages, 3 figures

References in corpus (5)

• Detecting Topological Currents in Graphene Superlattices
• Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures
• Strongly correlated two-dimensional plasma explored from entropy measurements
• Quantization of entropy in a quasi-two-dimensional electron gas
• Thermodynamic properties of the 2+1-dimensional Dirac fermions with broken time-reversal symmetry

Cited by in corpus (10)

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• Thermal difference reflectivity of tilted 2D Dirac materials
• Density of states and differential entropy in Dirac materials in crossed magnetic and in-plane electric fields
• Density of states measurements for heavy subband of holes in HgTe quantum wells
• Differential entropy per particle as a probe of van Hove singularities and flat bands
• Entropy and Seebeck signals meet on the edges
• Fermi surface instabilities of symmetry-breaking and topological types on the surface of a three-dimensional topological insulator