Mutual information between non-contractible regions on the torus fully classifies long-range nonstabilizerness for toric-code states but leaves a finite subset undetected in the doubled-Fibonacci string-net model.
Nonlocal nonstabilizerness in free fermion models
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
Nonlocal magic quantifies the irreducible nonstabilizerness of a bipartite quantum state after optimizing over local basis changes. We study nonlocal magic for pure fermionic Gaussian states, and derive a simple closed-form entanglement spectrum bound in terms of the singular values of the subsystem-restricted covariance matrix. We benchmark our result against simulated annealing over local Gaussian unitary transformations, which supports optimality along the full local Gaussian orbit. For states drawn from the Gaussian Haar ensemble, we show that the average nonlocal magic is extensive and determine its thermodynamic limit using random matrix theory for the appropriate circular unitary ensemble. We also study Gaussian ground states, focusing on the Kitaev chain, and find that nonlocal magic is suppressed deep in both trivial and topological phases and peaks near the critical points. Finally, we investigate Gaussian evolution via random circuits and in quenches with the XY chain. For random circuits, we find that nonlocal magic grows diffusively, while in the XY chain the XX limit reveals a striking separation between nonlocal magic and entanglement.
fields
quant-ph 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
Non-stabilizerness of the Hubbard dimer is computed with robustness of magic and stabilizer Rényi entropy, revealing it as a resource distinct from fermionic non-Gaussianity and superselected entanglement.
citing papers explorer
-
Long-range nonstabilizerness of topologically encoded states from mutual information
Mutual information between non-contractible regions on the torus fully classifies long-range nonstabilizerness for toric-code states but leaves a finite subset undetected in the doubled-Fibonacci string-net model.
-
Quantum magic of strongly correlated fermions $-$ the Hubbard dimer
Non-stabilizerness of the Hubbard dimer is computed with robustness of magic and stabilizer Rényi entropy, revealing it as a resource distinct from fermionic non-Gaussianity and superselected entanglement.