Fig. 3: Experimental result.
From: Integrated photonic source of Gottesman–Kitaev–Preskill qubits
a, Wigner function heralded by the (n1, n2, n3) = (3, 3, 3) PNR outcome with position, q, and momentum, p, quadrature probability (prob) distributions and symmetric, p and q effective squeezing (\({\varDelta }_{\text{sym}}^{2}\), \({\varDelta }_{p}^{2}\), and \({\varDelta }_{q}^{2}\), respectively) shown. White and grey homodyne bins corresponding to a rectangular GKP lattice indicating probability overlap with obtaining 0/1 and +/– outcomes. The state generated is a GKP \(| 1\rangle \) state on a rectangular lattice. b, Wigner functions of a subset of heralded states for different PNR heralding pattern, (n1, n2, n3): (1, 1, 1) shows a heralded cat state; (1, 3, 3), a GKP state with hexagonal lattice structure; and (3, 3, 5) and (4, 4, 4) show rectangular GKP states. States presented in a and b are reconstructed by state tomography using up to 2 × 106 quadrature measurements for the (1, 1, 1) and (1, 3, 3) state, and roughly 5.9 × 105, 3.6 × 105 and 1.9 × 106 quadrature measurements for the (3, 3, 5), (4, 4, 4) and (3, 3, 3) states, respectively. Each colour bar range shows the minimum and maximum of the corresponding Wigner function. The ħ = 1 convention is used.
