Probing the Critical Behavior of a Sign-Problematic Model with Monte Carlo Simulations

Abstract

The sign-problematic generalized Baxter-Wu (GBW) model with asymmetric complex couplings is mapped onto a one-dimensional quantum model. Utilizing the model's exactly known critical properties, we study the relation between the conventional and the modified average signs and the phase transitions in the GBW model. We find that the average sign develops a negative peak near the critical point, but it is not a unique indicator of phase transition, as similar features can appear in non-critical regions. While the average modified sign provides a viable probe for the phase transition, the practical effectiveness of this method is limited by the exponential scaling of computational cost with the system's volume. We propose that the universal properties of the original model can be investigated through simulating the related reference model, based on the universality assumption. Using finite-size scaling analysis based on Monte Carlo simulations, we confirm the validity of this method, which thereby provides a novel framework for investigating phase transitions in systems plagued by the sign problem.

9 pages, 8 figures

References in corpus (8)

• Computational complexity and fundamental limitations to fermionic quantum Monte Carlo simulations
• Universality and Critical Exponents of the Fermion Sign Problem
• Equivalent-neighbor Potts models in two dimensions
• A flexible class of exact Hubbard-Stratonovich transformations
• Strong ferromagnetic fluctuations in a doped checkerboard lattice
• Defining a universal sign to strictly probe a phase transition
• Scaling in the vicinity of the four-state Potts fixed point
• Boosting quantum Monte Carlo and alleviating sign problem by Gutzwiller projection