In the presence of more than two terminals in the system, the two terminals symmetry is broken. In the earlier given exemple, T 21 ≠ ≠ T 32 + T 13 . This is due to the fact that the terminals "recycle" the incoming electrons, for which the phase coherence is lost when another electron is emitted towards terminal 1. However, since the carriers are moving through edge states, one can see that T 21 B = T 12 − − B even with the presence of a third terminal. This is due to the fact that under magnetic field inversion, the edge states simply change their propagation orientation. This is especially true if terminal 3 is taken as a perfect potential probe.