The Majorana fermion, a particle that is its own antiparticle, was originally introduced as a putative elementary particle by Ettore Majorana in 1937, and the chiral Majorana fermion was experimentally observed in topological superconductors in 2017. Since the Majorana fermion is a charge-neutral particle, the direct effect on Majorana fermions by electromagnetic methods should fail. Now, researchers have proposed a scheme to control the transport of chiral Majorana edge modes in a ring-shaped Josephson junction of a topological superconductor using magnetic flux.