Resonating Valence-Bond State in an Orbitally Degenerate Quantum Magnet with Dynamical Jahn-Teller Effect

Abstract

Short-range resonating-valence bond states in an orbitally degenerate magnet on a honeycomb lattice is studied. A quantum-dimer model is derived from the Hamiltonian which represents the superexchange interaction and the dynamical Jahn-Teller (JT) effect. We introduce two local units termed "spin-orbital singlet dimer", where two spins in a nearest-neighbor bond form a singlet state associated with an orbital polarization along the bond, and "local JT singlet", where an orbital polarization is quenched due to the dynamical JT effect. A derived quantum-dimer model consists of the hopping of the spin-orbital singlet dimers and the JT singlets, and the chemical potential of the JT singlets. We analyze the model by the mean-field approximation, and find that a characteristic phase, termed "JT liquid phase", where both the spin-orbital singlet dimers and the JT singlets move quantum mechanically, is realized. Possible scenarios for the recently observed non magnetic-ordered state in Ba${}_3$CuSb${}_2$O${}_9$ are discussed.

arXiv comment8 pages, 7 figures

References in corpus (17)

• Spin Liquid State in an Organic Mott Insulator with Triangular Lattice
• Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2
• An RVB phase in the triangular lattice quantum dimer model
• Spin-Liquid State in the S = 1/2 Hyperkagome Antiferromagnet Na4Ir3O8
• Quantum Melting of Magnetic Order due to Orbital Fluctuations
• Orbital liquid in three dimensional Mott insulator: $LaTi{O}_3$
• Spin-orbital quantum liquid on the honeycomb lattice
• The phase diagram of the hexagonal lattice quantum dimer model
• A Spin-Orbital Singlet and Quantum Critical Point on the Diamond Lattice: FeSc2S4
• Orbital degeneracy as a source of frustration in LiNiO${}_2$
• Orbital and spin physics in LiNiO2 and NaNiO2
• Singlet Ground State of the Quantum Antiferromagnet Ba3CuSb2O9
• Identification of an RVB liquid phase in a quantum dimer model with competing kinetic terms
• A Generalized Quantum Dimer Model Applied to the Frustrated Heisenberg Model on the Square Lattice: Emergence of a Mixed Columnar-Plaquette Phase
• Exploring the spin-orbital ground state of Ba3CuSb2O9
• Dynamical Jahn-Teller Effect in Spin-Orbital Coupled System
• The emergence of Resonating Valence Bond physics in spin-orbital models

Cited by in corpus (10)

• Thermal Hall effect in a phonon-glass Ba${}_3$CuSb${}_2$O${}_9$
• Emergent $\mathrm{SU}(4)$ Symmetry in $\alpha$-ZrCl${}_3$ and Crystalline Spin-Orbital Liquids
• Randomness-induced quantum spin liquid behavior in the s=1/2 random J1-J2 Heisenberg antiferromagnet on the honeycomb lattice
• Absence of Jahn-Teller transition in the hexagonal Ba3CuSb2O9 single crystal
• Jahn-Teller effect in systems with strong on-site spin-orbit coupling
• Disorder driven spin-orbital liquid behaviour in the Ba${}_3$XSb${}_2$O${}_9$ materials
• Observation of the orbital quantum dynamics in the spin-1/2 hexagonal antiferromagnet Ba3CuSb2O9
• $\mathrm{SU}(4)$-Symmetric Quantum Spin-Orbital Liquids on Various Lattices
• Spin-Orbital Entangled Liquid State in the Copper Oxide Ba${}_3$CuSb${}_2$O${}_9$
• Orbiton-magnon interplay in the spin-orbital polarons of KCuF3 and LaMnO3