  Motivated by recent proposals of Majorana qubits and the read-out of their
quantum state we investigate a qubit setup formed by two parallel topological
wires shunted by a superconducting bridge. The wires are further coupled to two
quantum dots, which are also linked directly, thus creating an interference
loop. The transport current through this system shows an interference pattern
which distinguishes two basis states of the qubit in a QND measurement. We
analyze various properties of the interference current and the read-out
process, including the resulting dephasing and relaxation. We also analyze the
effects of varying control parameters such as gate voltages on the current. The
characteristic dependencies could serve as a signature of Majorana bound
states.
