We investigate the dynamical charge response in a "Majorana Coulomb box" realized by two Majorana bound states hosted at the ends of a mesoscopic topological superconductor. One side of the wire is coupled to a normal lead and low frequency gate voltage is applied to the system. There is no dc current; the system can be considered as an RC quantum circuit. We calculate the effective capacitance and charge relaxation resistance. The latter is in agreement with the Korringa-Shiba formula where, however, the charge relaxation resistance is equal to h/2e2. This value corresponds to the strong Coulomb blockade limit described by a resonant model formulated by Fu. We also performed direct calculations using the latter model and defined its parameters by direct comparison with our perturbation theory results.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 12 Dec 2012|