Kitaev-Heisenberg model on the star lattice: From chiral Majorana fermions to chiral triplons

Fuente: arXiv
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Auteurs principaux: d'Ornellas, Peru, Knolle, Johannes
Format: Preprint
Publié: 2023
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author d'Ornellas, Peru
Knolle, Johannes
author_facet d'Ornellas, Peru
Knolle, Johannes
contents The interplay of frustrated interactions and lattice geometry can lead to a variety of exotic quantum phases. Here we unearth a particularly rich phase diagram of the Kitaev-Heisenberg model on the star lattice, a triangle decorated honeycomb lattice breaking sublattice symmetry. In the antiferromagnetic regime, the interplay of Heisenberg coupling and geometric frustration leads to the formation of valence bond solid (VBS) phases -- a singlet VBS and a bond selective triplet VBS stabilized by the Kitaev exchange. We show that the ratio of the Kitaev versus Heisenberg exchange tunes between these VBS phases and chiral quantum spin liquid regimes. Remarkably, the VBS phases host a whole variety of chiral triplon excitations with high Chern numbers in the presence of a weak magnetic field. We discuss our results in light of a recently synthesized star lattice material and other decorated lattice systems.
format Preprint
id arxiv_https___arxiv_org_abs_2312_01967
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Kitaev-Heisenberg model on the star lattice: From chiral Majorana fermions to chiral triplons
d'Ornellas, Peru
Knolle, Johannes
Strongly Correlated Electrons
The interplay of frustrated interactions and lattice geometry can lead to a variety of exotic quantum phases. Here we unearth a particularly rich phase diagram of the Kitaev-Heisenberg model on the star lattice, a triangle decorated honeycomb lattice breaking sublattice symmetry. In the antiferromagnetic regime, the interplay of Heisenberg coupling and geometric frustration leads to the formation of valence bond solid (VBS) phases -- a singlet VBS and a bond selective triplet VBS stabilized by the Kitaev exchange. We show that the ratio of the Kitaev versus Heisenberg exchange tunes between these VBS phases and chiral quantum spin liquid regimes. Remarkably, the VBS phases host a whole variety of chiral triplon excitations with high Chern numbers in the presence of a weak magnetic field. We discuss our results in light of a recently synthesized star lattice material and other decorated lattice systems.
title Kitaev-Heisenberg model on the star lattice: From chiral Majorana fermions to chiral triplons
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2312.01967