  Discovery of the new two-dimensional (2D) Dirac semimetals incorporating both
superconductivity and the topological band structure has provided a novel
platform for realizing the intriguing applications of Dirac fermions and
Majorana quasiparticles, ranging from high-speed quantum devices at the
nanoscale to topological quantum computations. In this work, utilizing
first-principles calculations and symmetry analysis, we introduce MOH (M= Zr,
Hf) as a new topological superconductor with Dirac points close to a Fermi
level which are connected with nearly flat edge states as a striking feature of
topological semimetals. Our calculations show that ZrOH as a 2D topological
semimetal can exhibit superconductivity and is a novel platform for studying
the interplay between superconductivity and Dirac states in low-dimensional
materials.
