  We propose a new family of the d0 orbital XY (X = K, Rb, Cs; Y = N, P, As,
Sb, Bi) monolayers with abundant and novel topology and valley properties. The
KN, RbN, RbP, RbAs, CsP, CsAs, and CsSb monolayers possess remarkable quantum
anomalous Hall effect (QAHE). CsSb monolayer also exhibits extraordinary valley
QAHE with giant splitting. Moreover, the topological properties of XY
monolayers can be effciently tuned by the in-plane strain, owing to the
strain-induced band inversion between the px;y and pz orbitals. Our findings
suggest that the d0 orbital XY monolayers can be good candidates for promising
applications in the spintronics and multifunctional topological-based devices.
