Conductance Peak Splitting in the Coulomb Blockade as Signature of Spin Interactions

We investigate the transport properties of a quantum dot coupled to leads interacting with a spin system using the generalized master equation within the Coulomb blockade regime. We find that if two states for each scattering region electron manifold are included, multiple consequences of the interacting spin system appear in steady-state transport properties. We predict multiple peaks in conductance, as opposed to the single peak expected in traditional Coulomb blockade experiments, related to the inclusion of excited state transitions between uncharged and charged electron manifolds. We find that by adjusting the exchange coupling of the transitory electron with the spin system, these conductance features turn on and off. This prediction opens the possibility of using electron current to measure the exchange coupling strength between the itinerant electron and spin system.