Figure 1

(Color online) (a) Schematics of single-electron tunneling through a discrete quantum level, ${\mu }_D$, together with the reservoir Fermi levels, ${\mu }_{L/R}$, and density of states. (b) Schematic stability diagram showing conductance through the discrete quantum level as a function of the source-drain bias and the plunger gate voltage. The numbered lines of increased conductance arise from the corresponding DOS peaks in panel (a). (c) Zeeman splitting of the reservoir and discrete energy levels in a magnetic field.Reuse & Permissions

Figure 2

(Color online) (a) Top view of structure A and (b) structure B and a schematic cross section of (c) structure A and (d) structure B in the $y=0$ plane. The insets show schematic potential landscapes along $x$.Reuse & Permissions

Figure 3

(Color online) Conductance of (a) structure A with $V_{\text{lg}}=1.87\text{V}$ and $B=4\text{T}$ and (c) structure B with $V_{\text{lg}}=3.00\text{V}$, $V_{\text{lb}}=0.52\text{V}$, $V_{\text{rb}}=0.68\text{V}$, and $B=0\text{T}$ as a function of the source-drain bias and the plunger gate voltage. The dashed line in panel (a) represents the trace shown in panel (b) for $V_{\text{sd}}=-2.5\text{mV}$ as a function of the lead gate voltage for differential conductance. Panel (d) corresponds to the dashed trace shown in panel (c) for $\Delta V_{\text{pg}}=2.1\text{mV}$ from the transport window at $V_{\text{sd}}=0$. The capacitive coupling of the lead gate to the donor or the dot has been compensated by the plunger gate, in structure A by finding the Coulomb peak at $V_{\text{sd}}=0$ for each trace and in structure B by a voltage shift $-\Delta V_{\text{lg}}/80$ at the plunger. The resulting average voltage shift for structure A was $-0.04\times \Delta V_{\text{lg}}$.Reuse & Permissions

Figure 4

(Color online) [(a)–(c)] Stability diagrams of structure A in magnetic fields ranging from 1 to 6 T. The spin excited state [L6 in panel (a)] is marked with a white and blue arrow, and the DOS lines are labeled with green arrows. (d) Shift of the conductance lines in magnetic field. Data for each line is offset in energy for clarity. The dashed lines show a slope $2{\mu }_B$ for L6 and ${\mu }_B$ for the other data.Reuse & Permissions