beta-Cu2V2O7: a spin-1/2 honeycomb lattice system

Abstract

We report on band structure calculations and a microscopic model of the low-dimensional magnet beta-Cu2V2O7. Magnetic properties of this compound can be described by a spin-1/2 anisotropic honeycomb lattice model with the averaged coupling \bar J1=60-66 K. The low symmetry of the crystal structure leads to two inequivalent couplings J1 and J1', but this weak spatial anisotropy does not affect the essential physics of the honeycomb spin lattice. The structural realization of the honeycomb lattice is highly non-trivial: the leading interactions J1 and J1' run via double bridges of VO4 tetrahedra between spatially separated Cu atoms, while the interactions between structural nearest neighbors are negligible. The non-negligible inter-plane coupling Jperp~15 K gives rise to the long-range magnetic ordering at TN~26 K. Our model simulations improve the fit of the magnetic susceptibility data, compared to the previously assumed spin-chain models. Additionally, the simulated ordering temperature of 27 K is in remarkable agreement with the experiment. Our study evaluates beta-Cu2V2O7 as the best available experimental realization of the spin-1/2 Heisenberg model on the honeycomb lattice. We also provide an instructive comparison of different band structure codes and computational approaches to the evaluation of exchange couplings in magnetic insulators.

11 pages, 10 figures, 2 tables: revised version, extended description of simulation results

References in corpus (10)

• The ALPS project release 1.3: open source software for strongly correlated systems
• Generalized Directed Loop Method for Quantum Monte Carlo Simulations
• Anisotropy and Magnetism in the LSDA+U Method
• Disorder in a quantum spin liquid: flux binding and local moment formation
• Extension of the spin-1/2 frustrated square lattice model: the case of layered vanadium phosphates
• Spin-gap phase of a quantum spin system on a honeycomb lattice
• Magnetic Excitations of Spin-Gap System Na3Cu2SbO6 with Distorted Honeycomb Structure
• Quantum Phase Transition, O(3) Universality Class and Phase Diagram of Spin-1/2 Heisenberg Antiferromagnet on Distorted Honeycomb Lattice: A Tensor Renormalization Group Study
• Large quantum fluctuations in the strongly coupled spin-1/2 chains of green dioptase: a hidden message from birds and trees
• Structural distortion and frustrated magnetic interactions in the layered copper oxychloride [CuCl]LaNb(2)O(7)

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