Scheme to measure Majorana fermion lifetimes using a quantum dot

We propose a setup to measure the lifetime of the parity of a pair of Majorana bound states. The proposed experiment has one edge Majorana state tunnel coupled to a quantum dot, which in turn is coupled to a metallic electrode. When the Majorana fermions overlap, even a small relaxation rate qualitatively changes the nonlinear transport spectrum, and for strong overlap the lifetime can be read off directly from the height of a current peak. This is important for the usage of Majorana fermions as a platform for topological quantum computing, where the parity relaxation is a limiting factor.