When an atomic/molecular system controlled by an external field (to imprint information on it, such as preparing a qubit), is brought near a plasmonic nanostructure, the control problem changes. On one hand, the field experienced by the atom is modified due to the plasmon effects of the nanostructure. On the other hand, due to atom-nanostructure interactions the quantum state spontaneous emission is increased. Purification of states is fundamental to the implementation of quantum technologies. My approach for state purification is based on the interplay of control fields and spontaneous emission from a two-level quantum system in presence of a gold nanoparticle (GNP). For a specific location of the system around the GNP, I can find a control field that increases the purity of the system more than without the GNP. Unlike previous efforts of state purification that involve cooling to the ground state, here the excited state population remains significant
