Probing critical phases in quasiperiodic systems via subsystem information capacity
The study uses Subsystem Information Capacity (SIC) to probe critical phases in quasiperiodic systems, like the Aubry-André-Harper model. While standard entanglement measures fail to capture critical states' spatial complexity, SIC reveals pronounced spatial heterogeneity and unique dynamical signatures called 'subregion echoes.' These echoes are linked to underlying fragmentation, suggesting that SIC is a powerful tool for diagnosing the multifractal structure of criticality.