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Precision study of the massive Schwinger model near quantum criticality

Erick Arguello Cruz, Grigory Tarnopolsky, and Yuan Xin

Phys. Rev. D 112, 034023 – Published 22 August, 2025

DOI: https://doi.org/10.1103/vf7m-kzk2

Abstract

We perform a numerical analysis of the massive Schwinger model in the presence of a background electric field. Using the Density Matrix Renormalization Group approach, we efficiently compute the spectrum of the Schwinger model on a staggered lattice with up to 3000 qubits. As a result, we achieve a precise computation of the critical mass of the massive Schwinger model to five digits using four different “criticality criteria,” observing perfect agreement among them Additionally, we discuss the effect of a four-fermion operator deformation of the Schwinger model and compute the critical mass for various values of the deformation parameter.

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