Symmetry-resolved entanglement in lattice gauge theories: A tensor networks approach

We study gauge-symmetry-resolved entanglement in lattice gauge theories (LGTs). LGTs are useful as an approximation for continuum gauge field theories, as well as for being implementable many-body systems with topological order, making them candidates for fault-tolerant quantum computation. LGT is based on local symmetry, which makes natural the discussion of its symmetry-resolved properties, such as symmetry-resolved entanglement. This quantity, that is, the contribution to entanglement from each symmetry sector of the studied system, can point to relations between entanglement and symmetry, and isolate accessible entanglement when the local symmetry is enforced. We use tensor-network representations of LGT states to show the dependence of a subsystem's symmetry-resolved entanglement on the subsystem geometry and their relations with other model properties, such as confinement.