Power-law entanglement growth from typical product states

Understand

Generic quantum many-body systems typically show a linear growth of the entanglement entropy after a quench from a product state.

• While entanglement is a property of the wave function, it is generated by the unitary time evolution operator and is therefore reflected in its increasing complexity as quantified by the operator entanglement entropy.
• Using numerical simulations of a static and a periodically driven quantum spin chain, we show that there is a robust correspondence between the entanglement entropy growth of typical product states with the operator entanglement entropy of the unitary evolution operator, while special product states, e.g.
• $\sigma_z$ basis states, can exhibit faster entanglement production.