Spin effects of charged exciton states in electric field tunable quantum dot molecules

Tuning the relative energy levels in coupled quantum dots with an applied electric field results in controllable spin interactions of bound carriers. These interactions may provide new directions in engineering these systems for optical and spintronic applications. Using polarization resolved photoluminescence experiments we observe spin dependent effects in the spectra which vary as a function of applied field. As we tune the exciton emission we observe variations in circular polarization memory in the neutral exciton and in the singly charged exciton states. We propose possible mechanisms for externally manipulating the spin coupling.