- Editors' Suggestion
generalizations of three-dimensional stabilizer codes
Phys. Rev. B 112, 155136 – Published 16 October, 2025
DOI: https://doi.org/10.1103/qctl-hwvh
Abstract
In this work, we generalize several three-dimensional stabilizer models—including the X-cube model, the three-dimensional toric code, and Haah's code—to their counterparts. Under periodic boundary conditions, we analyze their ground state degeneracies and topological excitations and uncover behaviors that strongly depend on system size. For the X-cube model, we identify excitations with mobility restricted under local operations but relaxed under nonlocal ones derived from global topology. These excitations, previously confined to open boundaries in the model, now appear even under periodic boundaries. In the toric code, we observe nontrivial braiding between string and point excitations despite the absence of ground state degeneracy, indicating long-range entanglement independent of topological degeneracy. Again, this effect extends from open to periodic boundaries in the generalized models. For Haah's code, we find new excitations—fracton tripoles and monopoles—that remain globally constrained, along with a relaxation of immobility giving rise to lineons and planons. These results reveal new forms of topological order and suggest a broader framework for understanding fracton phases beyond the conventional setting.