Leaking a Majorana between a Kitaev chain and a Kitaev ring

Signatures of Majorana particles are in high demand since the zero-bias conductance peak, prominently featured in well-known attempts to realize Kitaev’s chain [1, 2] and therein considered as a signature of Majorana bound states, is, in fact, ubiquitous to a variety of transport measurements. Such peaks may appear in quantum dots due to the Kondo effect [3, 4], in metal-superconductor junctions from Andreev bound states [5], and in a range of disordered systems [6–9]. In this talk we consider a simple, magnetic-field free, setup consisting of a “Kitaev ring” - a closed Kitaev chain - coupled to one of the Majorana bound states of a Kitaev chain in the topological phase. We find that the band structures, spectral functions, occupation numbers and currents are sensitive to the edge-ring coupling in fundamentally different ways for couplings with a Majorana state versus a trivial fermion, thus serving as experimentally accessible signatures for telling a Majorana bound state from a trivial one.