Symmetry-protected topological order
= Symmetry-protected topological order
{wiki=Symmetry-protected_topological_order}
Symmetry-protected topological order (SPT order) is a concept in condensed matter physics and quantum many-body systems that describes certain phases of matter. These phases are characterized by long-range quantum entanglement and unusual global properties, and they exist in a manner that is robust against local perturbations, as long as certain symmetries are preserved.