Ferroelectricity and related effects on carrier transport in type-II Weyl semimetal WTe$_{2}$ thin film

TL;DR

This paper explores the coexistence of ferroelectricity and metallicity in WTe₂ thin films, revealing their influence on electrical transport and potential applications in energy-efficient data storage.

Contribution

It provides a theoretical and numerical analysis of ferroelectric polarization, electronic structure, and topological effects in type-II Weyl semimetal WTe₂, highlighting novel insights into its transport properties.

Findings

Ferroelectricity coexists with metallicity in bulk WTe₂.

Topological character influences electronic behaviors and excitations.

Hysteresis in WTe₂ suggests potential for non-volatile data storage.

Abstract

We investigate ferroelectric polariation as well as the formation of long-range order and the carrier density distribution in type-II Weyl semimetal WTe$_{2}$ in $T_{d}$ phase. It is been found that the metallicity and ferroelectricity can coexist in bulk WTe$_{2}$ which has a significant impact on the electrical transport\cite{Sharma}, despite its large conductance. Also, our theoretical calculation and numerical simulation provide a deeper insight to the electrical structure-dependent dynamics of WTe$_{2}$. Base on the two-level approximation verify that the polarization stems from uncompensated out-of-plane interband transition of the electrons, which is base on the calculations of the dipole transition moment (in both the momentum space and frequency domain), and we found that the topological character of type-II Weyl system is closely related to the electronic behaviors (like the carrier compensation) and the excitations near the Weyl cone. The anisotropy and the topologically protected spin-polarized bulk (Weyl orbit) and surface states in WTe$_{2}$ induce hysteresis, which exhibitspotential in applications of non-volatile energy-efficient data-storage devices. Part of the properties of WTe$_{2}$ are also shares shared by the thermoelectric properties with other two-dimensional transition-metal dichalcogenides, like the WSe$_{2}$ and MoTe$_{2}$.