Fig. 4: Exact diagonalization of a QED plaquette.
From: Tensor networks for lattice gauge theories beyond one dimension
a For a grid of masses and couplings m ∈ [10−2, 101] and g2 ∈ [10−1, 101], minimal gauge truncation ℓ* required to reach a precision ϵtrunc = 10−5 in the magnetic energy \(\langle {{{{\rm{Re}}}}}\,{\hat{U}}_{\square }\rangle\). b Scaling of ℓ* with g2 for m = 0.1. c Corresponding entanglement entropy S associated with a symmetric bipartition of the plaquette (see also Supplementary Note I and Fig. S1).
