2014/06/11 by András Molnár, Norbert Schuch, Frank Verstraete +2 · 5 citations
Computer Science · Mathematics · Physics and Astronomy · #Combinatorics #Dimension (graph theory) #Geometry #Lattice (music) #Mathematical physics #Mathematics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum and electron transport phenomena #Quantum many-body systems #Quantum mechanics #Scaling #cond-mat.stat-mech #cond-mat.str-el #quant-ph
paper · pdf · doi:10.1103/physrevb.91.045138
published as Phys. Rev. B 91, 045138 (2015) · 12 pages, 1 figure
arxiv created 2014/06/11 · openalex publication_date 2015/01/29 · arxiv updated 2015/02/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We analyze the error of approximating Gibbs states of local quantum spin Hamiltonians on lattices with projected entangled pair states (PEPS) as a function of the bond dimension (D), temperature (\ensuremathβ^\ensuremath-1), and system size (N). First, we introduce a compression method in which the bond dimension scales as D=e^O(log22(N/\ensuremathε)) if \ensuremathβ<O(log2N). Second, building on the work of Hastings [M. B. Hastings, Phys. Rev. B 73, 085115 (2006)], we derive a polynomial scaling relation, D=(N/\ensuremathε)^O(\ensuremathβ). This implies that the manifold of PEPS forms an efficient representation of Gibbs states of local quantum Hamiltonians. From those bounds it also follows that ground states can be approximated with D=N^O(log2N) whenever the density of states only grows polynomially in the system size. All results hold for any spatial dimension of the lattice.