Extended Data Fig. 8: Dynamics in double wells.

Under the same superlattice configuration, we measure the evolution of three different states in double wells. The initial states are |10⟩ (blue squares), |11⟩ (orange triangles) and |20⟩ (red circles). The state |10⟩ oscillates with almost the full amplitude. The superexchange interaction drives the spin exchange process as expected. In contrast, the atom population remains constant for the state |20⟩. Error bars, s.d. The solid curves are exponentially damped sinusoidal fittings, where the frequency, phase and decay rate are fixed. We find that the oscillation amplitude of tunnelling is almost three orders of magnitude larger than the other two fitting values.