Pauli Spin Blockade — Energy-Level Anticrossing (2D)

The same double-quantum-dot readout physics as the 3D geometric simulator, redrawn as the diagram physicists actually use to explain it: an energy-vs-detuning plot. Prepare a singlet or one of three triplets, then pulse the detuning ε across a real avoided crossing computed from a two-level Hamiltonian (gap = 2t_c) — the singlet branch bends smoothly from the (1,1) energy onto the (0,2) energy, while every Pauli-blocked triplet line stays flat and simply passes through the crossing untouched. A live strip chart shows the resulting charge-sensor signal shot by shot, and the same stochastic tunnelling-rate model as the 3D version drives single-shot outcomes and a running fidelity counter, so the two simulators reproduce identical statistics from two different, equally genuine physical pictures.