Three-orbital continuous model for $1H$-type metallic transition-metal dichalcogenide monolayers

Abstract

We theoretically investigate the electronic states in monolayer NbSe${}_2$ and develop continuous models to describe these states in Fermi pockets. In $1H$-type metallic transition-metal dichalcogenides(TMDCs), the Femi surface consists of three pockets enclosing the $\Gamma$, $K$, and $K^{\prime }$ points. We reveal that the conventional effective model used for semiconducting TMDCs is not sufficient to describe the electronic states in metallic TMDCs and thus introduce a scheme to construct the effective model from the first-principles results. All models can be represented by $3\times 3$ Hamiltonian and well reproduce electronic states around the Fermi energy in terms of the orbital composition and the phase factor. We also show that the $p$ orbitals in chalcogen atoms, which are ignored in the conventional $2\times 2$ model, play a crucial role in metallic TMDCs. Although the aim of these models is to reproduce electronic states, they can well describe states near the high-symmetry points and the profile of Berry curvature in the wave vector space. The continuous model can be a handleable tool to describe the electronic states and to analyze the transport phenomena in metallic TMDCs.

13 pages, 10 figures

References in corpus (4)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• Quasiparticle band structures and optical properties of strained monolayer MoS2 and WS2
• Spin-dependent Refraction at the Atomic Step of Transition-metal Dichalcogenides

Cited by in corpus (1)

• Intrinsic spin-valley locking for conducting electrons in metal-semiconductor-metal lateral hetero-structures of $1H$-transition-metal dichalcogenides