Fig. 1
Observation of coherent effects. a A scanning electron micrograph of the quantum-dot-forming region in a lithographically identical device: The three circles represent the estimated location of three dots. The squares represent ohmic contacts. The grey scale bar pictured at left represents 500 nm. b The charge stability diagram, which maps out the ground state electron occupancy of the three dots as a function of side gate voltages: c A close-up of interference fringes at the (0,1,1)↔(1,0,1) charge transition: A 500 ps square pulse with an amplitude of +30 mV is placed on V L. The 0 detuning line is shown as a dotted line and the detuning axis is shown as a solid arrow. d Time domain oscillations: Fixing V L and V R at values within the interference region and fixing the pulse height at +24 mV, the nominal time of the square pulse is varied, resulting in an oscillatory average charge occupation. Error bars are the one standard deviation range for that data point as taken over 10 averages. Also shown is a fitted decaying sinusoid used to extract a frequency (4.41 ± 0.01 GHz here) and decay time (0.90 ± 0.04 ns), the latter of which serves as a lower bound on \(T_2^*\). A moving average with a window of several periods of the oscillation has been subtracted prior to fitting to counteract pulse duty cycle effects
