Generalized Entanglement, Charges and Intertwiners

Understand

The entanglement theory in quantum systems with internal symmetries is rich due to the spontaneous creation of entangled pairs of charge/anti-charge particles at the entangling surface.

• We call these pair creation operators the bi-local intertwiners because of the role they play in the representation theory of the symmetry group.
• We define a generalized measure of entanglement entropy as a measure of information erased under restriction to a subspace of observables.
• We argue that the correct entanglement measure in the presence of charges is the sum of two terms; one measuring the entanglement of charge-neutral operators, and the other measuring the contribution of the bi-local intertwiners.