  We consider the logarithmic negativity and related quantities of time
evolution operators. We study free fermion, compact boson, and holographic
conformal field theories (CFTs) as well as numerical simulations of random
unitary circuits and integrable and chaotic spin chains. The holographic
behavior strongly deviates from known non-holographic CFT results and displays
clear signatures of maximal scrambling. Intriguingly, the random unitary
circuits display nearly identical behavior to the holographic channels.
Generically, we find the "line-tension picture" to effectively capture the
entanglement dynamics for ergodic systems and the "quasi-particle picture" for
integrable systems. With this motivation, we propose an effective line-tension
that captures the dynamics of the logarithmic negativity in ergodic systems in
the spacetime scaling limit. We compare the negativity and mutual information
leading us to find distinct dynamics of quantum and classical information. The
"spurious entanglement" we observe may have implications on the
"simulatability" of quantum systems on classical computers. Finally, we
elucidate the connection between the operation of partially transposing a
density matrix in conformal field theory and the entanglement wedge cross
section in Anti-de Sitter space using geodesic Witten diagrams.
