Ground-State Phase Diagram of (1/2,1/2,1) Mixed Diamond Chains

Abstract

The ground-state phases of mixed diamond chains with ($S,{\tau }^{(1)},{\tau }^{(2)})=(1/2,1/2,1)$, where $S$ is the magnitude of vertex spins, and ${\tau }^{(1)}$ and ${\tau }^{(2)}$ are those of apical spins, are investigated. The two apical spins in each unit cell are coupled by an exchange coupling $\lambda$. The vertex spins are coupled with the top and bottom apical spins by exchange couplings $1+\delta$ and $1-\delta$, respectively. Although this model has an infinite number of local conservation laws for $\delta =0$, they are lost for finite $\delta$. The ground-state phase diagram is determined using the numerical exact diagonalization and DMRG method in addition to the analytical approximations in various limiting cases. The phase diagram consists of a nonmagnetic phase and several kinds of ferrimagnetic phases. We find two different ferrimagnetic phases without spontaneous translational symmetry breakdown. It is also found that the quantized ferrimagnetic phases with large spatial periodicities present for $\delta =0$ are easily destroyed by small $\delta$ and replaced by a partial ferrimagnetic phase. The nonmagnetic phase is considered to be a gapless Tomonaga-Luttinger liquid phase based on the recently extended Lieb-Schultz-Mattis theorem to the site-reflection invariant spin chains and numerical diagonalization results.

arXiv comment8 pages, 10 figures

References in corpus (9)

• Magnetization plateaus in spin chains: ``Haldane gap'' for half-integer spins
• Ground states with cluster structures in a frustrated Heisenberg chain
• Lattice Homotopy Constraints on Phases of Quantum Magnets
• General Lieb-Schultz-Mattis type theorems for quantum spin chains
• Spontaneously magnetized Tomonaga-Luttinger liquid in frustrated quantum antiferromagnets
• Effective field theory for one-dimensional valence-bond-solid phases and their symmetry protection
• Lieb-Schultz-Mattis theorem with a local twist for general one-dimensional quantum systems
• Ground State Phase Diagram of S=1 Diamond Chains
• Infinite Series of Ferrimagnetic Phases Emergent from the Gapless Spin Liquid Phase of Mixed Diamond Chains

Cited by in corpus (1)

• Ground-State Phase Diagram of (1/2,1/2,1) Mixed Diamond Chains with Single-Site Anisotropy