Fig. 1.

Superconducting double dot and its energy levels. a Scanning electron micrograph of the InSb nanowire device, green circles indicate positions of the two quantum dots. The two superconducting leads are S _L and S _R. The double dots are defined and tuned by five local gates: V _SL, V _L, V _t, V _R, and V _SR. The direction of magnetic field B is indicated by arrow. b Spectrum of Andreev states in two quantum dots separated by a large barrier as a function of detuning $ϵ$. On the left (right) dot, the ground states are $∣S_{\mathrm{L}\left(\mathrm{R}\right)}⟩$, $∣D_{\mathrm{L}\left(\mathrm{R}\right)}⟩$ and $∣S_{\mathrm{L}\left(\mathrm{R}\right)}⟩$ with dot occupations 2, 1, 0 (0, 1, 2), respectively. Vertical lines connect levels that hybridize to form molecular states plotted in d. c Molecular Andreev spectrum of a double quantum dot as a function of detuning (main panel) and energy level shift (inset). S(2,0) denotes singlet (2,0) configuration and similar for others. Charge configurations in b, c are labeled in b and separated by dashed lines. d Transport resonance at positive bias occurs when Andreev chemical potentials −ζ _L(V _L, μ _S), and ζ _R(V _R, μ _D) are aligned and bias (V_bias) compensates relaxation energies. The hashed bars depict subgap states included in the numerical model