Charge Fractionalization in a Mesoscopic Ring

We study the fractionalization of an electron tunneling into a strongly interacting electronic one-dimensional ring. As a complement to transport measurements in quantum wires connected to leads, we propose noninvasive measures involving the magnetic field profile around the ring to probe this fractionalization. In particular, we show that the magnetic field squared produced by the electron and the power that it would induce in a detector exhibit anisotropic profiles that depend on the degree of fractionalization. We contrast true fractionalization with two other scenarios which could mimic it-quantum superposition and classical probabilistic electron insertion. We show that the proposed field-dependent measures and those of the persistent current can distinguish between these three scenarios. DOI: 10.1103/PhysRevLett.110.026402