Preempting fermion sign problem: Unveiling quantum criticality through nonequilibrium dynamics in imaginary time.

ABSTRACT: The notorious fermion sign problem, arising from fermion statistics, presents a fundamental obstacle to the numerical simulation of quantum many-body systems. Here, we introduce a framework that circumvents the sign problem in the studies of quantum criticality and its associated phases by leveraging imaginary-time nonequilibrium critical dynamics. We demonstrate that the critical properties can be accurately determined from the system's short-time relaxation, a regime where the sign problem remains manageable for quantum Monte Carlo simulations. After validating this approach on two benchmark fermionic models, we apply it to the sign-problematic Hubbard model hosting SU(3)-symmetric Dirac fermions. We present the first numerically exact characterization of its quantum phase diagram, revea

SUBMITTER: Yu YK 

PROVIDER: S-EPMC12757072 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature