Basic properties of three-leg Heisenberg tube

TL;DR

This study investigates the ground state properties of a three-leg antiferromagnetic Heisenberg model with frustrated spins due to triangular rungs, revealing a persistent spin gap and dimerization order that intensify with rung coupling.

Contribution

It provides the first detailed analysis of the spin excitation gap and dimerization in a frustrated three-leg Heisenberg tube using DMRG.

Findings

Spin excitations are always gapped for nonzero rung coupling.

Spin-Peierls dimerization order is confirmed in the leg direction.

Both the spin gap and dimerization order increase with rung coupling.

Abstract

We study three-leg antiferromagnetic Heisenberg model with the periodic boundary conditions in the rung direction. Since the rungs form regular triangles, spin frustration is induced. We use the density-matrix renormalization group method to investigate the ground state. We find that the spin excitations are always gapped to remove the spin frustration as long as the rung coupling is nonzero. We also visibly confirm spin-Peierls dimerization order in the leg direction. Both the spin gap and the dimerization order are basically enhanced as the rung coupling increases.