Figure 1

(Color online) Scanning electron micrograph of a hybrid device. The P donors are implanted close to an induced SiSET (gray dashed square). The SiSET is formed by two gate controlled $\left(V_{\text{B}1},V_{\text{B}2}\right)$ tunnel junctions and the overlapping top gate. Panel (b) displays a close up of the stability diagram near the charge transition of a center with large charge-transfer signal $\Delta q\sim 0.6e$. A large gate voltage scan is shown in (c), where various charge transitions from multiple centers are visible.Reuse & Permissions

Figure 2

(Color online) Charge stability diagram for the pulsed voltage spectroscopy. (a) Sketch of the SiSET conductance as function of the top-gate voltage $V_{\text{T}}$ and the dc component of the donor control gate $V_{\text{D}0}$. Drawn as black (gray) lines are the positions of the Coulomb peaks when the added pulse voltage $V_{\text{P}}=V_{\text{L}}=0\text{V}$ $\left(V_{\text{P}}=V_{\text{H}}\right)$. The dotted lines are guides to the eye to indicate a slice of the hexagonal charge stability diagram characteristic for a double dot system. When the frequency of the square wave $f_{\text{P}}$ for switching between $V_{\text{L}}$ and $V_{\text{H}}$ is much smaller than the tunneling rates ${\Gamma }_{\text{c}}$ and ${\Gamma }_{\text{e}}$, the current corresponding to the black lines on the right in panel (a) stop at the dotted line because the charge configuration can follow the equilibrium state. Panel (b) shows this behavior, where $f_{\text{P}}=61.3\text{Hz}$ with duty cycle $d=0.5$. In contrast, when $2\pi f_{\text{P}}⪢{\Gamma }_{\text{c}}$, ${\Gamma }_{\text{e}}$, a nonequilibrium charge configuration can be observed, resulting in current along the thick dashed orange lines extending from the black lines in panel (a). Panel (c) displays $I_{\text{SET}}$ for $f_{\text{P}}=5.12\text{kHz}$, where additional current is visible in this area. Panel (d) shows the schematic for the pulsed voltage imposing a charge transition, indicating the various relevant times for the rate equation model as described in the text.Reuse & Permissions

Figure 3

(Color online) Intensity ratios of the Coulomb peaks for points in the charge stability diagram [cf. Fig. 2a] and time ratios originating from the rate equation model (dashed lines). Panel (a) shows the peak ratios as functions of the pulse frequency $f_{\text{P}}$ for a duty cycle of 0.5. The dashed lines represent the model using a capture and emission rate of ${\Gamma }_{\text{c}}={\Gamma }_{\text{e}}=3000{\text{s}}^{-1}$. Panels (b) and (c) show the same ratios as a function of the duty cycle for a fixed $f_{\text{P}}$ of 61.3 Hz and 613 Hz, respectively, where experiment and model are in good agreement. Additionally, the red filled circles are the Coulomb peak ratios outside the region of the charge transition. They show good agreement with the ratios of ${\tau }_{\text{H}}$ and ${\tau }_{\text{L}}$ depending on the duty cycle $d$.Reuse & Permissions