Imaging bond order near non-magnetic impurities in square lattice antiferromagnets

TL;DR

This paper investigates the local bond order textures near non-magnetic impurities in square lattice antiferromagnets using field theories and quantum Monte Carlo simulations, revealing vortex structures in the order parameter.

Contribution

It introduces a field theoretic description of impurity-induced vortex structures in bond order and verifies these with numerical simulations, extending to cuprate-like density waves.

Findings

Vortex structures in bond order near impurities

Verification of field theory with quantum Monte Carlo data

Extension to cuprate density wave phenomena

Abstract

We study the textures of generalized "charge densities" (scalar objects invariant under time reversal), in the vicinity of non-magnetic impurities in square-lattice quantum anti-ferromagnets, by order parameter field theories. Our central finding is the structure of the "vortex" in the generalized density wave order parameter centered at the non-magnetic impurity. Using exact numerical data from quantum Monte Carlo simulations on an antiferromagnetic spin model, we are able to verify the results of our field theoretic study. We extend our phenomenological approach to the period-4 bond-centered density wave found in the underdoped cuprates.