2022/10/11 by Robert Maxton, Maxton, Robert, Yannick Meurice +1
Computer Science · #Advanced Data Storage Technologies #Cellular Automata and Applications #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Theory (hep-th) #Quantum Computing Algorithms and Architecture #Quantum Physics (quant-ph) #Statistical Mechanics (cond-mat.stat-mech)
paper · pdf · doi:10.48550/arxiv.2210.05493
openalex publication_date 2022/10/11 · openalex created_date 2022/10/14 · openalex updated_date 2026/07/28
The real time evolution of quantum field theory models can be calculated order by order in perturbation theory. For λϕ4 models, the perturbative series have a zero radius of convergence which in part motivated the design of digitized versions suitable for quantum computing. In agreement with general arguments suggesting that a large field cutoff modifies Dyson's reasoning and improves convergence properties, we show that the harmonic digitizations of λϕ4 lattice field theories lead to weak coupling expansions with a finite radius of convergence. Similar convergence properties are found for strong coupling expansions. We compare the resources needed to calculate the real-time evolution of the digitized models with perturbative expansions to those needed to do so with universal quantum computers. Unless new approximate methods can be designed to calculate long perturbative series for large systems efficiently, it appears that the use of universal quantum computers with digitizations involving a few qubits per site has the potential for more efficient calculations of the real-time evolution for large systems at intermediate coupling.