Honeycomb antiferromagnet with a triply degenerate dimer ground state

2009/06/01 by Rakesh Kumar, Dushyant Kumar, Brijesh Kumar
Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Degenerate energy levels #Dimer #Ground state #Heisenberg model #Lattice (music) #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum many-body systems #Quantum mechanics #Spin (aerodynamics) #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.80.214428

published as Phys. Rev. B 80, 214428 (2009) · 6+ pages, 10 figures, submitted to Phys. Rev. B

arxiv created 2009/06/01 · openalex publication_date 2009/12/30 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We present an antiferromagnetic quantum spin-1/2 model on honeycomb lattice. It has two parts, one of which is the usual nearest-neighbor Heisenberg model. The other part is a certain multiple spin interaction term, introduced by us, which is exactly solvable for the ground state. Without the Heisenberg part, the model has an exact threefold degenerate dimer ground state. This exact ground state is also noted to exist for the general spin-S case. For the spin-1/2 case, we further carry out the triplon analysis in the ground state to study the competition between the Heisenberg and the multiple spin interactions. This approximate calculation exhibits a continuous quantum phase transition from the dimer order to N'eel order.

Citations

• Fourfold degenerate columnar-dimer ground state in square lattice antiferromagnets
• On Next-Nearest-Neighbor Interaction in Linear Chain. I
• Phase diagram of the hexagonal lattice quantum dimer model
• Frustrated Honeycomb Heisenberg Antiferromagnet: A Schwinger Boson Approach
• Quantum disordered ground states in frustrated antiferromagnets with multiple ring exchange interactions
• Critical Exponents of the Quantum Phase Transition in a Planar Antiferromagnet
• Deconfined Quantum Critical Points