Non-local coupling with phase lag α produces chimera states: coexisting synchronized and desynchronized populations.
R = — (order parameter)
θ̇ᵢ = ωᵢ + K/N Σⱼ G(i,j)sin(θⱼ-θᵢ-α)
Kuramoto-Sakaguchi (1986) with non-local coupling G(i,j)=exp(-κ|i-j|²/2σ²). Chimeras discovered by Kuramoto & Battogtokh (2002) — paradoxical coexistence of order and chaos in identical oscillators.