Square-root growth of operator entanglement in an integrable brickwork circuit
The study investigates operator entanglement in an integrable four-state brickwork circuit, where it exhibits square-root growth ($ ext{Sop}^1(t) o rac{ ext{log } 2ar{ au}}{ar{ au}}/ ext{t}$), contrary to expected logarithmic bounds. This counterexample arises from the specific gate structure and domain-wall quench, demonstrating that integrability does not guarantee the usual logarithmic entanglement scaling for local operators.