Figure 2: Spin read-out and relaxation rates for single-electron occupancy.
From: Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting
(a) Schematic diagram showing the effect of the three-level pulse sequence on the electro-chemical potential of the dot. Energy levels in the QD are Zeeman split according to spin polarization and valley degeneracy is lifted. For clarity, only lower valley states are shown to be loaded/unloaded. (b) Pulsing sequence (top) for the single-shot spin read-out and normalised SET signal for spin-up (middle) and spin-down (bottom). (c) Energy diagram of the one-electron spin-valley states as a function of B field. Maximum mixing of spin and valley degrees of freedom occurs at the anticrossing point where Zeeman and valley splittings coincide. Relevant relaxation processes are sketched. (d) Relaxation rates as a function of magnetic field for different valley splittings. Data points for EVS=0.75 meV, EVS=0.33 meV are shown as green and red circles, respectively. Dashed lines are the calculated relaxation rates fitted with r=1.7 nm (green), r=1.1 nm (red).
