Researchers Identify New Methods to Detect Chirality in Complex States

Researchers in the School of Physics, working with King Fahd University of Petroleum and Minerals, have found that standard methods for identifying chirality in topological phases fail when applied to mixed quantum states. The study reveals that established diagnostics, including bulk-boundary correspondence and the modular commutator, are unreliable in these complex systems. Consequently, the research presents two new measures, based on relative entropy, to accurately diagnose chirality and determine the chiral central charge in decohered topological phases, indicating a need for a new set of tools when investigating mixed-state topology.