  We study the transport properties of an interferometer composed by a quantum
dot (QD) coupled with two normal leads and two one-dimensional topological
superconductor nanowires (TNWs) hosting Majorana bound states (MBS) at their
ends. The geometry considered is such that one TNW has both ends connected with
the QD, forming an Aharonov-Bohm (AB) interferometer threaded by an external
magnetic flux, while the other TNW is placed near the interferometer TNW. This
geometry can alternatively be seen as a long wire contacted across a local
defect, with possible coupling between independent-MBS. We use the Green's
function formalism to calculate the conductance across normal current leads on
the QD. We find that the conductance exhibits a half-quantum value regardless
of the AB phase and location of the dot energy level, whenever the
interferometer configuration interacts with the neighboring TNW. These findings
suggest that such a geometry could be used for a sensitive detection of MBS
interactions across TNWs, exploiting the high sensitivity of conductance to the
AB phase in the interferometer.
