Problems / mathematical-physics
mathematical-physics / Quantum many-body systems; entanglement and spectral gaps
The entanglement area law for gapped ground states in two dimensions
Theorem 1.1: for fixed q,R,J,Δ there is C such that for every finite induced domain Λ⊂Z2 and every Hamiltonian of range R and term norm J with a unique ground vector Ω and H−E0≥Δ(1−∣Ω⟩⟨Ω∣), every A⊆Λ has SΩ(A)≤C∣∂ΛA∣. Corollary 1.2 gives the vertex-boundary forms. The companion proves that on open L×L grids with nearest-neighbour interactions the ground state has a PEPS approximation of bond dimension CLc and global error L−1. It does not treat dimensions three and higher, Renyi entropies, or degenerate ground states, and gives no explicit constant.