Decorated Shastry-Sutherland lattice in the spin-1/2 magnet CdCu2(BO3)2

Abstract

We report the microscopic magnetic model for the spin-1/2 Heisenberg system CdCu2(BO3)2, one of the few quantum magnets showing the 1/2-magnetization plateau. Recent neutron diffraction experiments on this compound [M. Hase et al., Phys. Rev. B 80, 104405 (2009)] evidenced long-range magnetic order, inconsistent with the previously suggested phenomenological magnetic model of isolated dimers and spin chains. Based on extensive density-functional theory band structure calculations, exact diagonalizations, quantum Monte Carlo simulations, third-order perturbation theory, as well as high-field magnetization measurements, we find that the magnetic properties of CdCu2(BO3)2 are accounted for by a frustrated quasi-2D magnetic model featuring four inequivalent exchange couplings: the leading antiferromagnetic coupling J_d within the structural Cu2O6 dimers, two interdimer couplings J_t1 and J_t2, forming magnetic tetramers, and a ferromagnetic coupling J_it between the tetramers. Based on comparison to the experimental data, we evaluate the ratios of the leading couplings J_d : J_t1 : J_t2 : J_it = 1 : 0.20 : 0.45 : -0.30, with J_d of about 178 K. The inequivalence of J_t1 and J_t2 largely lifts the frustration and triggers long-range antiferromagnetic ordering. The proposed model accounts correctly for the different magnetic moments localized on structurally inequivalent Cu atoms in the ground-state magnetic configuration. We extensively analyze the magnetic properties of this model, including a detailed description of the magnetically ordered ground state and its evolution in magnetic field with particular emphasis on the 1/2-magnetization plateau. Our results establish remarkable analogies to the Shastry-Sutherland model of SrCu2(BO3)2, and characterize the closely related CdCu2(BO3)2 as a material realization for the spin-1/2 decorated anisotropic Shastry-Sutherland lattice.

16 pages, 13 figures, 2 tables. Published version with additional QMC data

References in corpus (21)

• A class of quantum many-body states that can be efficiently simulated
• Classical simulation of infinite-size quantum lattice systems in two spatial dimensions
• The ALPS project release 1.3: open source software for strongly correlated systems
• Anisotropy and Magnetism in the LSDA+U Method
• beta-Cu2V2O7: a spin-1/2 honeycomb lattice system
• Extension of the spin-1/2 frustrated square lattice model: the case of layered vanadium phosphates
• Toward Perfection: Kapellasite, Cu3Zn(OH)6Cl2, a New Model S = 1/2 Kagome Antiferromagnet
• Modified kagome physics in the natural spin-1/2 kagome lattice systems - kapellasite Cu3Zn(OH)6Cl2 and haydeeite Cu3Mg(OH)6Cl2
• Absence of magnetic order for the spin-half Heisenberg antiferromagnet on the star lattice
• Coupled Cluster Treatment of the Shastry-Sutherland Antiferromagnet
• Eighth-order high-temperature expansion for general Heisenberg Hamiltonians
• Structural and magnetic dimers in the spin-gapped system CuTe2O5
• Sr${}_2$Cu(PO${}_4$)${}_2$: A real material realization of the 1D nearest neighbor Heisenberg chain
• A Novel Ordered Phase in SrCu2(BO3)2 under High Pressure
• Peculiar long-range superexchange in Cu2A2O7 (A = P, As, V) as a key element of the microscopic magnetic model
• Coupled frustrated quantum spin-1/2 chains with orbital order in volborthite Cu3V2O7(OH)2(H2O)2
• Large quantum fluctuations in the strongly coupled spin-1/2 chains of green dioptase: a hidden message from birds and trees
• Magnetic properties of the low-dimensional spin-1/2 magnet α-Cu_2As_2O_7
• In-Gap Spin Excitations and Finite Triplet Lifetimes in the Dilute Singlet Ground State System SrCu(2-x)Mgx(BO3)2
• Proposed low energy model Hamiltonian for spin-gapped system CuTe2O5
• Emergence of One-Dimensional Physics from the Distorted Shastry-Sutherland Lattice

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