Open Type Nodal line Topological Semimetal in Two Dimensional B2C

TL;DR

This study predicts a two-dimensional B2C monolayer that hosts coexisting nodal line and Dirac semimetals, with distinct energy windows, offering a new platform for exploring topological semimetal properties.

Contribution

It reveals the coexistence of nodal line and Dirac semimetals in 2D B2C, with distinct energy windows, and provides a tight-binding model for their electronic structure.

Findings

Coexistence of nodal line and Dirac semimetals in 2D B2C.

Distinct energy windows for different topological semimetals.

Potential for experimental distinction and study of semimetal interplay.

Abstract

Topological semimetals, including Dirac semimetals, Weyl semimetals, and nodal line semimetals, receive enormous research interest due to their intrinsic topological nature and fascinating properties. In present work, with the help of density functional theory (DFT), we find that nodal line semimetals and Dirac semimetals can coexist in the low energy electron of two dimensional (2D) monolayer B2C. Intriguingly, besides type-I and type-II Dirac fermions, a kind of open nodal line appears around the Fermi level. The low energy electronic nature of B2C sheet can be described by a tight-binding (TB) model relied on the basis of B-py, pz and C-py, pz states. One of the most merit of the system is that the energy windows of these four types topological semimetals are different that can be easily distinguished in experiments. Moreover, the system provides an excellent platform for studying the interplay between different type semimetals.