Exponential orthogonality catastrophe and logarithmic lightcone in many-body localized systems
Recently, many-body localization (MBL) has attracted tremendous interest, both theoretical and experimental. MBL phases show a cornucopia of exotic features, such as violation of ergodicity, emergent integrability, and localization-protected orders, etc. In this talk, I will present some recent results on the orthogonality catastrophe and logarithmic lightcone in MBL systems. I will show that, in spite of localization, a local quench can induce an exponential orthogonality catastrophe, where the typical wave-function overlap between the pre- and post-quench eigenstates decays exponentially with the system size. In addition, the local quench triggers entanglement growth throughout the whole system. By comparing the post-quench entanglement dynamics for different bipartitions, a logarithmic lightcone can be explicitly demonstrated in MBL systems.
Hosted by Mohammad Hafezi and Charles Clark.