Gapped Dirac semimetal with mixed linear and parabolic dispersions

Abstract

In this paper, we make a comprehensive study of the properties of a gapped Dirac semimetal model, which was originally proposed in the magnetoinfrared spectroscopy measurement of ZeTe${}_5$, and includes both the linear and parabolic dispersions in all three directions. We find that, depending on the band inversion parameters, ${\zeta }^{\prime }$ and ${\zeta }_z^{\prime }$, the model can support three different phases: the single Dirac point (DP) phase, the double DPs phase and the Dirac ring phase. The three different phases can be distinguished by their low-energy features in the density of states (DOS) and optical conductivity. At high energy, both the DOS and optical conductivity exhibit power-law like behaviors, with the asymptotic exponents depending heavily on the signs of ${\zeta }^{\prime }$ and ${\zeta }_z^{\prime }$. Moreover, the thumb-of-rule formula between the DOS and optical conductivity is satisfied only when $({\zeta }^{\prime },{\zeta }_z^{\prime })>0$. The implications of our results for experiments are discussed.

8 pages, 5 figures

References in corpus (8)

• Classification of topological insulators and superconductors in three spatial dimensions
• Evidence for a Strong Topological Insulator Phase in $\mathrm{ZrT}{\mathrm{e}}_5$
• Spectroscopic evidence for bulk-band inversion and three-dimensional massive Dirac fermions in ZrTe5
• Low frequency optical conductivity in graphene and in other scale-invariant two-band systems
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Cited by in corpus (4)

• Quantum oscillations and three-dimensional quantum Hall effect in ZrTe${}_5$
• Unconventional optical selection rules in ZrTe5 under an in-plane magnetic field
• Magnetic field driven Lifshitz transition and one-dimensional Weyl nodes in three-dimensional pentatellurides
• Magneto-optic signatures in the gapped Dirac semimetal with mixed linear and parabolic dispersions of ZrTe5