  We discuss devices for detection of the topological insulator phase based on
the two-path electron interference. For that purpose we consider buckled
silicene for which a local energy gap can be opened by vertical electric field
to close one of the paths and for which the quantum spin Hall insulator
conditions are controlled by the Fermi energy. In quantum spin Hall phase the
interference is absent due to the separation of the spin currents and the
conductance of the devices include sharp features related to localized
resonances. In the normal transport conditions the two-path interference
produces a regular Aharonov-Bohm oscillations in the external magnetic field.
