  Kitaev chain (KC) is a prototypical model for the study of Majorana fermions
(MFs). In the topological phase, a KC hosts two MFs at its ends. Being
separated in space, these two MFs are nonlocal. The nonlocal transport in a KC
biased between two normal metal leads is mediated by electron tunneling (ET)
and crossed Andreev reflection (CAR). ET contributes positively while CAR
contributes negatively to the nonlocal conductance. Enhanced CAR and hence a
negative nonlocal conductance is a hallmark of nonlocality of MFs. But simple
conductance measurements in the above setup cannot probe the nonlocality of MFs
due to the almost cancellation of currents from ET and CAR. On the other hand,
a Josephson junction between two KCs hosts two Andreev bound states (ABSs) at
the junction formed by a recombination of Majorana fermions of the individual
KCs. The energies of the ABSs are away from zero and can be changed by altering
the superconducting phase difference. A Josephson junction between two finitely
long KCs hosts two MFs at the two ends and two ABSs at the junction. We show
that when normal metal leads are connected to two ends of such a Josephson
junction, the nonlocal conductance of the setup can be negative for bias values
equal to the energies of the ABSs. Thus the nonlocal conductance in such setup
can probe the nonlocality of the constituent MFs.
