  Two-dimensional (2D) materials, especially their most prominent member,
graphene, have greatly influenced many scientific areas. Moreover, they have
become a base for investigating the relativistic properties of condensed matter
within the emerging field of Dirac physics. This has ignited an intense search
for new materials where charge carriers behave as massless or massive Dirac
fermions. Here, we theoretically show the existence of Dirac electrons in a
series of 2D transition-metal carbides, known as MXenes. They possess twelve
conical crossings in the 1st Brillouin zone with giant spin-orbit splitting.
Our findings indicate that the 2D band structure of MXenes is protected against
external perturbations and preserved even in multilayer phases. These results,
together with the broad possibilities to engineer the properties of these
materials phases, make Dirac MXenes a potential candidate for studying and
developing novel Dirac-physics-based technologies.
