Manipulation of a single charge in a double quantum dot
  We manipulate a single electron in a fully tunable double quantum dot using microwave excitation. Under resonant conditions, microwaves drive transitions between the (1,0) and (0,1) charge states of the double dot. Local quantum point contact charge detectors enable a direct measurement of the photon-induced change in occupancy of the charge states. From charge sensing measurements, we find T1~16 ns and a lower bound estimate for T2* of 400 ps for the charge two-level system. 
J. R. Petta, A. C. Johnson, C. M. Marcus, M. P. Hanson, A. C. Gossard