Pulsed-gate measurements of the singlet-triplet relaxation time in a   two-electron double quantum dot
  A pulsed-gate technique with charge sensing is used to measure the singlet-triplet relaxation time for nearly-degenerate spin states in a two-electron double quantum dot. Transitions from the (1,1) charge occupancy state to the (0,2) state, measured as a function of pulse cycle duration and magnetic field, allow the (1,1) singlet-triplet relaxation time (~70 microseconds) and the (0,2) singlet-triplet splitting to be measured. The use of charge sensing rather than current measurement allows long relaxation times to be readily probed. 
J. R. Petta, A. C. Johnson, A. Yacoby, C. M. Marcus, M. P. Hanson, A.   C. Gossard