Spread complexity and localization in PT -symmetric systems

This study investigates the behavior of wave functions in parity-time ({P}{T}) symmetric quantum systems, focusing on their spread and localization. Using a tight-binding chain model, the authors explore the dynamics under {P}{T} symmetry and its breaking. By employing innovative quantum information measures, such as complexity, entropy, and inverse participation ratio in Krylov space, they quantify the wave function's distribution. In the {P}{T}-symmetric phase, the wave function spreads evenly, while {P}{T} symmetry breaking leads to localization, exemplifying the non-Hermitian skin effect and edge modes.