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arXiv · 1904.00090

Dielectric and electronic properties of three-dimensional Luttinger semimetals with a quadratic band touching

Serguei Tchoumakov·William Witczak-Krempa
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Abstract

Due to strong spin-orbit coupling, charge carriers in three-dimensional quadratic band touching Luttinger semimetals have non-trivial wavefunctions characterized by a pseudospin of 3/2. We compute the dielectric permittivity of such semimetals at finite doping, within the random phase approximation. Because of interband coupling, the dielectric screening shows a reduced plasma frequency and an increased spectral weight at small wavevectors, compared to a regular quadratic band. This weakens the effective Coulomb potential, modifying the single-particle self-energy for which we present both analytical and numerical results. At a low carrier density, the quasiparticle properties of this model strongly deviate from that of a single quadratic band. We compare our findings with experimental results for alpha-Sn, HgSe, HgTe, YPtBi and Pr2Ir2O7.

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Serguei Tchoumakov, William Witczak-Krempa. 2020-01-29. Dielectric and electronic properties of three-dimensional Luttinger semimetals with a quadratic band touching. https://doi.org/10.1103/physrevb.100.075104

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