Stabilizer Rényi Entropy Encodes Fusion Rules of Topological Defects and Boundaries
Phys. Rev. Lett. 136, 080402 – Published 25 February, 2026
DOI: https://doi.org/10.1103/1tyr-rlbb
Abstract
We demonstrate that the stabilizer Rényi entropy (SRE), a computable measure of quantum magic, can serve as an information-theoretic probe for universal properties associated with conformal defects in one-dimensional quantum critical systems. Using boundary conformal field theory, we show that open boundaries manifest as a universal logarithmic correction to the SRE, whereas topological defects yield a universal size-independent term. When multiple defects are present, we find that the universal terms in the SRE faithfully reflect the defect-fusion rules that define a noninvertible symmtery algebra. These analytical predictions are corroborated by numerical calculations of the Ising model, where boundaries and topological defects are described by Cardy states and Verlinde lines, respectively.