Frustrated quantum spin systems in small triangular lattices studied with a numerical method

TL;DR

This paper introduces a simple numerical approach using exact diagonalization with engineered boundary conditions to study quantum frustrated spin systems on small triangular lattices, providing insights into their phase diagrams.

Contribution

The authors develop an accessible computational method for analyzing small frustrated quantum spin systems, offering results consistent with more complex techniques.

Findings

Qualitative agreement with 2D-DMRG and variational quantum Monte Carlo results.

Effective characterization of quantum phase diagrams in small triangular lattices.

Demonstration of the method's applicability to diverse antiferromagnetic models.

Abstract

The study of quantum frustrated systems remains one of the most challenging subjects of quantum magnetism, as they can hold quantum spin liquids, whose characterization is quite elusive. The presence of gapped quantum spin liquids possessing long range entanglement while being locally indistinguishable often demand highly sophisticated numerical approaches for their description. Here we propose an easy computational method based on exact diagonalization with engineered boundary conditions in very small plaquettes. We apply the method to study the quantum phase diagram of diverse antiferromagnetic frustrated Heisenberg models in the triangular lattice. Our results are in qualitative agreement with previous results obtained by means of sophisticated methods like 2D-DMRG or variational quantum Monte Carlo.