Analyzing the two-dimensional doped Hubbard model with the Worldvolume HMC method

Abstract

We apply the Worldvolume Hybrid Monte Carlo (WV-HMC) method [arXiv:2012.08468] to the two-dimensional Hubbard model, which is known to suffer from a severe sign problem when the system is doped (away from half filling). We show that the method predicts physical observables with controlled statistical errors on an $8\times 8$ lattice at temperature $T/t=1/6.4\approx 0.156$ and interaction strength $U/t=8.0$ ($t$ is the hopping amplitude), for which the standard determinant quantum Monte Carlo fails.

10 pages, 3 figures, contribution to the 42nd International Symposium on Lattice Field Theory (LATTICE2025), 2-8 November 2025, Mumbai, India