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Long-range order and low-energy spectrum of diluted 2D quantum AF

A. L. Chernyshev·Y. C. Chen·A. H. Castro Neto
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Abstract

The problem of diluted two-dimensional (2D) quantum antiferromagnet (AF) on a square lattice is studied using spin-wave theory. The influence of impurities on static and dynamic properties is investigated and a good agreement with experiments and Monte Carlo (MC) data is found. The hydrodynamic description of spin-waves breaks down at characteristic wavelengths $Λ\agt\exp(\frac{const}{x})$, $x$ being an impurity concentration, while the order parameter is free from anomalies. We argue that this dichotomy originates from strong scattering of the low-energy excitations in 2D.

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A. L. Chernyshev, Y. C. Chen, A. H. Castro Neto. 2001-06-13. Long-range order and low-energy spectrum of diluted 2D quantum AF. https://doi.org/10.1103/physrevlett.87.067209

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