Lee--Yang Zeros and Pseudocritical Drift in J-Q N'eel Antiferromagnet--Valence-Bond Solid Transitions
The study uses Lee-Yang zeros from quantum Monte Carlo to probe transitions between Néel antiferromagnets and columnar valence-bond solids in J-Q models. The findings show a systematic drift in these zeros with increasing system size, suggesting an extended pseudocritical regime consistent with a weakly first-order transition.