  Using the Kane-Mele-Hubbard model in the unrestricted mean field
approximation, the effect of spin-orbit coupling, as an intrinsic parameter,
and an in-plane transverse electric field, as an external parameter, on the
electronic and magnetic properties of honeycomb zigzag nanoribbons are
investigated in the presence of electron-electron interaction. Our calculations
show that each of these parameters has significant effects on the physical
properties of nanoribbons, and each of them independently transitions the
nanoribbon from a magnetic to non-magnetic state. The process of change in some
aspect of physical properties, such as symmetry breaking, separation of spin up
and spin down energy bands, reduction of magnetic order, change of electric
dipole moment and spin current of nanoribbons, which are due to change of these
two parameters are investigated. we will see that spin-orbit coupling in the
competition with the transverse electric field determines the basic physical
properties of the nanoribbon. This research, can provide a better understanding
of two types of topological and non-topological transitions. In addition, the
separation of spin-up and spin-down energy bands and their tuning by these
parameters can be considered as a candidate for use in spintronic instruments.
