Macroscopic ground state degeneracy of the ferro-antiferromagnetic Heisenberg model on diamond-decorated lattices
arXiv:2504.04129 · doi:10.1103/drjr-wt6n
Abstract
We investigate the spin-1/2 Heisenberg model with competing ferromagnetic and antiferromagnetic interactions on diamond-decorated lattices. Tuning the exchange interactions to the boundary of the ferromagnetic phase, we analyze the models with two types of diamond units: distorted and ideal diamonds. In the distorted diamond model, flat bands in the magnon spectra indicate the localized states confined to small regions (`trapping cells') of the lattice. Remarkably, these trapping cells can host up to five and seven localized states for square and cubic lattices, respectively, leading to the macroscopic ground state degeneracy and high value of residual entropy. The problem of calculating ground state degeneracy reduces to that of non-interacting spins, whose spin value equal to half the number of localized magnons in the trapping cell. In contrast, ideal diamond models feature ground states composed of randomly distributed isolated diamond diagonal singlets immersed in a ferromagnetic background. Counting the ground state degeneracies here maps onto the percolation problem in 2D and 3D lattices. Our analysis shows that ideal diamond models possess even greater ground state degeneracy than their distorted counterparts. These findings suggest that synthesizing diamond-decorated-type compounds holds great promise for low-temperature cooling applications.
34 pages, 12 figures
References in corpus (20)
- Recent advances in percolation theory and its applications
- Enhanced magnetocaloric effect in frustrated magnets
- Strongly correlated flat-band systems: The route from Heisenberg spins to Hubbard electrons
- Exact low-temperature behavior of kagome antiferromagnet at high fields
- Magnetocaloric effect in one-dimensional antiferromagnets
- Exact eigenstates and macroscopic magnetization jumps in strongly frustrated spin lattices
- Universal low-temperature behavior of frustrated quantum antiferromagnets in the vicinity of the saturation field
- Universal properties of highly frustrated quantum magnets in strong magnetic fields
- Magnetocaloric effect in two-dimensional spin-1/2 antiferromagnets
- Thermodynamic properties of BaCoSiOCl in strong magnetic field: Realization of flat-band physics in a highly frustrated quantum magnet
- Thermodynamics of delta-chain with ferro- and antiferromagnetic interactions
- Flat-band physics in the spin-1/2 sawtooth chain
- Frustrated magnetism of spin-1/2 Heisenberg diamond and octahedral chains as a statistical-mechanical monomer-dimer problem
- Exact Realization of a Quantum-Dimer Model in Heisenberg Antiferromagnets on a Diamond-Like Decorated Lattice
- Phases of the spin-1/2 Heisenberg antiferromagnet on the diamond-decorated square lattice in a magnetic field
- The delta-chain with ferro- and antiferromagnetic interactions in applied magnetic field
- Spin dynamics and 1/3 magnetization plateau in a coupled distorted diamond chain compound K2Cu3(MoO4)4
- Thermodynamic properties of the macroscopically degenerate tetramer-dimer phase of the spin-1/2 Heisenberg model on the diamond-decorated square lattice
- Two-dimensional spin models with macroscopic degeneracy
- Macroscopic degeneracy of ground state in the frustrated Heisenberg diamond chain