Affiliation:
1. Donostia International Physics Center
2. Institute for Theoretical Physics, University of Innsbruck
3. Paul Scherrer Institute
4. École Polytechnique Fédérale de Lausanne
Abstract
The hunt for exotic quantum phase transitions described by emergent fractionalized degrees of freedom coupled to gauge fields requires a precise determination of the fixed point structure from the field theoretical side, and an extreme sensitivity to weak first-order transitions from the numerical side. Addressing the latter, we revive the classic definition of the order parameter in the limit of a vanishing external field at the transition. We demonstrate that this widely understood, yet so far unused approach provides a diagnostic test for first-order versus continuous behavior that is distinctly more sensitive than current methods. We first apply it to the family of QQ-state Potts models, where the nature of the transition is continuous for Q≤4Q≤4 and turns (weakly) first order for Q>4Q>4, using an infinite system matrix product state implementation. We then employ this new approach to address the unsettled question of deconfined quantum criticality in the S=1/2S=1/2 Néel to valence bond solid transition in two dimensions, focusing on the square lattice JJ-QQ model. Our quantum Monte Carlo simulations reveal that both order parameters remain finite at the transition, directly confirming a first-order scenario with wide reaching implications in condensed matter and quantum field theory.
Funder
Austrian Science Fund
Ministerio de Ciencia e Innovación
Subject
General Physics and Astronomy
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献