Spin Frustration, Magnetic Susceptibility and Excitations in Spatially Anisotropic Triangular-Lattice Antiferromagnets

ORAL

Abstract

We calculate the temperature dependent magnetic susceptibility and excitation spectra for the spatially anisotropic triangular- lattice Heisenberg model. We show that suitably scaled plots of magnetic susceptibility provide a direct measure of frustration in the system and allow one to infer the exchange parameters from the susceptibility data. We find that the organic material $\kappa-(BEDT-TTF)_2Cu_2(CN)_3$ is very well described by the isotropic triangular lattice model. We also find that the excitation spectra of the model shows various anomalies in the Neel and Spiral phases.

*Supported in Part by NSF-DMR-0240918

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Authors

  • Rajiv Singh

    • University of California, Davis
    • University of California at Davis

  • Weihong Zheng

    • University of New South Wales
    • University of New South Wales, Sydney, Australia

  • John Fjaerestad

    • University of Queensland

  • Ross McKenzie

    • University of Queensland
    • University of Queensland, Brisbane, Australia

  • Radu Coldea

    • University of Bristol, UK