Probing intraband excitations in ZrTe5 : A high-pressure infrared and transport study

Abstract

Zirconium pentatetelluride, ZrTe5, shows remarkable sensitivity to hydrostatic pressure. In this work we address the high-pressure transport and optical properties of this compound, on samples grown by flux and charge vapor transport. The high-pressure resistivity is measured up to 2 GPa, and the infrared transmission up to 9 GPa. The dc conductivity anisotropy is determined using a microstructured sample. Together, the transport and optical measurements allow us to discern band parameters with and without the hydrostatic pressure, in particular the Fermi level, and the effective mass in the less conducting, out-of-plane direction. The results are interpreted within a simple two-band model characterized by a Dirac-like, linear in-plane band dispersion, and a parabolic out-of-plane dispersion.arXiv:1912.00942v2 [cond-mat.mtrl-sci]

Distinguishing the gapped and Weyl semimetal scenario in ZrTe5 : Insights from an effective two-band model

“…This constant value is shown in Fig. 5 in blue, and it is very close to the experimentally obtained value R expt yx ≈ 2 [14]. In contrast to Eq.…”

“…This is accompanied by the anisotropic linearity of the bands along the intralayer (x, y) directions and the parabolic dispersion in the weakly dispersive out-of-plane z direction. This model provided an explanation of experimental data [9,14], in particular the square-root dependence of the optical conductivity at very low photon energies, in contrast to the linear dependence found in 3DD semimetals [8,15,16]. It also allowed us to estimate the energy interval in which the simple two-band model applies.…”

“…This qualitatively different behavior of R zx as a function of n is the key to distinguish the GMS from the WSM in DC transport, under the condition that the samples can be chemically or electrostatically doped. Experimentally, one can measure the anisotropy R zx , for example, using microfabricated samples [14]. Using expressions for effective carrier concentrations, Eqs.…”

Correlated interaction effects in three-dimensional semi-Dirac semimetal

“…The subsequent study about magnetotransport properties of ZrTe 5 under hydrostatic pressure also supports the existence of 3D semi-DSM phase [63]. Recent measurements of optical spectroscopy in ZrTe 5 are also consistent with 3D semi-DSM phase [64,65]. 3D semi-DSM state was also realized in pressed Cd 3 As 2 [66].…”

High-harmonic generation in semi-Dirac and Weyl semimetals with broken time-reversal symmetry: exploring the case of multiple semi-Dirac points

“…38,39 The semi-Dirac regime is exemplified by materials like SrNbO 3 and ZrTe 5 . 1,6,[39][40][41][42][43][44][45][46] In the recent study 47 (referenced multiple times in this paper), we investigated a model describing a transition from WSMs with broken time-reversal symmetry (TRS) to the semi-Dirac regime. In that study, we clarified that the contributions to the response in the regime with well-separated Weyl nodes 48,49 stem from the non-linearities in the dispersion, becoming particularly pronounced when the nodes approach each other.…”