Figure 1

(a)–(c) DOS vs energy and external barrier height ($V_{\mathrm{bar}1}/V_{\max }$); high DOS: dark area; low DOS: bright area. (a) Single dot, above: potential with external barriers $V_{\mathrm{bar}1}$ (left); micrograph of a gated sample (right). (b) Two-dot array, above: potential with $V_{\mathrm{bar}1}$ (left); PD at $V_{\mathrm{bar}1}/V_{\max }=0.06$ (*) (right). (c) Two-dot array as in (b), above: PDs for $V_{\mathrm{bar}1}/V_{\max }=0$ (**) and 0.2 (***). (d) Conductance: $V_{\mathrm{bar}1}/V_{\max }=0$ for a single-dot (red, thick dashed line) and a two-dot array (black, thick line), $V_{\mathrm{bar}1}/V_{\max }=0.2$ ($V_{\mathrm{bar}1}=4.72\mathrm{meV}$) for a single-dot (red, thin dashed line) and a two-dot array (black, thin line). Insets: PD (at the solid blue circles) for (i)–(v). (i)–(iii) Regular pointer states; (iv),(v): bipartite states. (e) PD for the 1st, 2nd, 6th, and 14th modes at (iv). $B=0.2\mathrm{T}$ and $V_{\max }=23.6\mathrm{meV}$ in all cases.Reuse & Permissions

Figure 2

Top: Potential landscapes for a closed two-dot system ($V_{\mathrm{bar}1}=\mathrm{\text{infinite}}$) with the coupling strength $V_{\mathrm{bar}2}/V_{\max }$ between the two dots progressively increased. (a) $V_{\mathrm{bar}2}/V_{\max }=0$ ($V_{\mathrm{bar}2}=0\mathrm{meV}$), (b) $V_{\mathrm{bar}2}/V_{\max }=0.05$ ($V_{\mathrm{bar}2}=1.18\mathrm{meV}$), and (c) $V_{\mathrm{bar}2}/V_{\max }=0.2$ ($V_{\mathrm{bar}2}=4.72\mathrm{meV}$). Bottom: The corresponding eigenstates. Eigenstate (a) has the same energy as state (iv) of Fig. 1. (d) Attempt of reconstruction of state (a) using single-dot eigenstates. $B$ and $V_{\max }$ as in Fig. 1.Reuse & Permissions

Figure 3

(a) Part of the Poincaré section (at $y=0$ for $v_y>0$) in the 2nd dot ($B=0.2\mathrm{T}$, $E=8.70\mathrm{meV}$). The attractors are labeled with $n=1$, 2, and 3. Five different initial conditions corresponding to: red (attracted by $n=1$); yellow, cyan (by $n=2$); and green, white (by $n=3$). (b) Top: Trajectory for $n=2$. Bottom: Zoom on the trajectory oscillating within $d_2$ and starting at $x=0.364068\mu \mathrm{m}$ (on $n=2$). Sharp red line: Trajectory with $d_1=0$, starting at $x=0.364143\mu \mathrm{m}$ (fixed point). (c) $x$ positions of the intersections of the trajectories with $y=0$ ($v_y>0$) for initial conditions in the basin of $n=1$, 2, and 3 vs the number $i$ of the consecutive intersections. Red arrow in (a) and (c): Example of an initial condition for a trajectory approaching attractor $n=3$. The periods of the oscillations are too short ($\Delta i<100$) to be resolved on the scale displayed.Reuse & Permissions