Corrections to scaling in the critical theory of deconfined criticality

TL;DR

This paper uses the functional renormalization group to analyze the quantum critical field theory of deconfined criticality, revealing corrections to scaling that explain slow convergence in numerical studies.

Contribution

It introduces a novel FRG approach with full wave-function renormalization dependence, providing insights into corrections to scaling in deconfined criticality.

Findings

Critical exponents align with some quantum Monte Carlo results.

Identifies small irrelevant eigenvalues causing strong corrections to scaling.

Explains slow convergence in numerical simulations.

Abstract

Inspired by recent conflicting views on the order of the phase transition from an antiferromagnetic Neel state to a valence bond solid, we use the functional renormalization group to study the underlying quantum critical field theory which couples two complex matter fields to a non-compact gauge field. In our functional renormalization group approach we only expand in covariant derivatives of the fields and use a truncation in which the full field dependence of all wave-function renormalization functions is kept. While we do find critical exponents which agree well with some quantum Monte Carlo studies and support the scenario of deconfined criticality, we also obtain an irrelevant eigenvalue of small magnitude, leading to strong corrections to scaling and slow convergence in related numerical studies.