Strange correlations in spin-1 Heisenberg antiferromagnets

TL;DR

This paper investigates the strange correlator in spin-1 Heisenberg antiferromagnets, demonstrating its effectiveness in identifying topological phases and analyzing critical behavior at quantum phase transitions.

Contribution

It applies projective quantum Monte Carlo to study the strange correlator across various phases, confirming its utility in distinguishing topological from trivial phases in spin-1 systems.

Findings

Strange correlator exhibits long-range behavior in symmetry-protected topological phases.

Successfully verifies topological nature of spin ladders.

Demonstrates the correlator's power in phase distinction.

Abstract

We study the behavior of the recently proposed "strange correlator" [Phys. Rev. Lett. {\bf 112}, 247202 (2014)] in spin-1 Heisenberg antiferromagnetic chains with uniaxial single-ion anisotropy. Using projective quantum Monte Carlo, we are able to directly access the strange correlator in a variety of phases, as well as to examine its critical behavior at the quantum phase transition between trivial and non-trivial symmetry protected topological phases. After finding the expected long-range behavior in these two symmetry conserving phases, we go on to verify the topological nature of two-leg and three-leg spin-1 Heisenberg antiferromagnetic ladders. This demonstrates the power of the strange correlator in distinguishing between trivial and non-trivial symmetry protected topological phases.