Chiral-mediated entanglement in an Aharonov-Bohm ring

We study the orbital entanglement in a biased Aharonov-Bohm ring connected in a four-terminal setup. We find that the concurrence achieves a maximum when the magnetic flux B coincides with an integer number of a half flux quantum 0 /2. We show that this behavior is a consequence of the existence of degenerate states of the ring having opposite chirality. We also analyze the behavior of the noise as a function of and discuss the reliability of this quantity as evidence of entanglement.