|Title||Logarithmic entanglement lightcone in many-body localized systems|
|Publication Type||Journal Article|
|Year of Publication||2017|
|Authors||D-L. Deng, X. Li, J.. H. Pixley, Y-. Le Wu, and D. S. Sarma|
|Journal||PHYSICAL REVIEW B|
|Date Published||JAN 10|
We theoretically study the response of a many-body localized system to a local quench from a quantum information perspective. We find that the local quench triggers entanglement growth throughout the whole system, giving rise to a logarithmic lightcone. This saturates the modified Lieb-Robinson bound for quantum information propagation in many-body localized systems previously conjectured based on the existence of local integrals of motion. In addition, near the localization-delocalization transition, we find that the final states after the local quench exhibit volume-law entanglement. We also show that the local quench induces a deterministic orthogonality catastrophe for highly excited eigenstates, where the typical wave-function overlap between the pre- and postquench eigenstates decays exponentially with the system size.