Create Dirac Cones in Your Favorite Materials

TL;DR

This paper presents a theoretical method to engineer Dirac cones in various two-dimensional materials, enabling the design of materials with tailored electronic properties similar to graphene.

Contribution

A novel theoretical recipe to create and control Dirac cones in any two-dimensional lattice, expanding possibilities beyond graphene.

Findings

Validates the theory with square lattice examples

Shows how to induce Dirac cones via vacancies, substitution, or intercalation

Applicable to electronic, photonic, and atomic systems

Abstract

Realization of conically linear dispersion, termed as Dirac cones, has recently opened up exciting opportunities for high-performance devices that make use of the peculiar transport properties of the massless carriers. A good example of current fashion is the heavily studied graphene, a single atomic layered graphite. It not only offers a prototype of Dirac physics in the field of condensed matter and materials science, but also provides a playground of various exotic phenomena. In the meantime, numerous routes have been attempted to search for the next "graphene". Despite these efforts, to date there is still no simple guideline to predict and engineer such massless particles in materials. Here, we propose a theoretical recipe to create Dirac cones into anyone's favorite materials. The method allows to tailor the properties, such as anisotropy and quantity, in any effective one-band two-dimensional lattice. We demonstrate the validity of our theory with two examples on the square lattice, an "unlikely" candidate hosting Dirac cones, and show that a graphene-like low-energy electronic structure can be realized. The proposed recipe can be applied in real materials via introduction of vacancy, substitution or intercalation, and also extended to photonic crystal, molecular array, and cold atoms systems.