Fig. 5: Noisy stabilizer in the surface code.
From: Quantum process tomography with unsupervised learning and tensor networks
a A X-stabilizer plaquette embedded into the surface code (left) and the quantum circuit performing the parity-check measurement (right), containing Hadamard and CX gates. b Purity of the LPDO Choi matrix during training (markers), compared to the exact Choi matrix (solid lines). c Infidelity measurement during training for a data set size of M = 5 × 105 single-shot measurement outcomes.
