Fig. 3: Noise-induced quantum synchronization.

a The local z-polarizations \(\langle {\sigma }_{j}^{z}\rangle\) of a chain of five qubits do not synchronize during noise-free unitary dynamics. b Synchronized oscillations, with frequency  ~ 2J = 20 MHz, between c qubits 1–5 and d qubits 2–4 occur, when Gaussian white noise with strength γ = 1.3 is applied to the third spin. The associated unsynchronized unitary evolution is shown in the background. e Pearson correlation coefficients C₁₅ and C₂₄ of qubits 1–5 and qubits 2–4 (symbols) converge to one, indicating perfect correlation between the corresponding qubits. The synchronized regime, C_ij ≥ 0.9, is attained for Jt ≥ 3π (red arrow). Good agreement with theory (solid lines) is obtained.