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arXiv · 1106.1008

The J1-J2 Heisenberg model at and close to its z=4 quantum critical point

J. Sirker·V. Y. Krivnov·D. V. Dmitriev·A. Herzog·O. Janson·S. Nishimoto·S. -L. Drechsler·J. Richter
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Abstract

We study the frustrated J1-J2 Heisenberg model with ferromagnetic nearest neighbor coupling J1<0 and antiferromagnetic next-nearest neighbor coupling J2>0 at and close to the z=4 quantum critical point (QCP) at J1/J2=-4. The J1-J2 model plays an important role for recently synthesized chain cuprates as well as in supersymmetric Yang Mills theories. We study the thermodynamic properties using field theory, a modified spin-wave theory as well as numerical density-matrix renormalization group calculations. Furthermore, we compare with results for the classical model obtained by analytical methods and Monte-Carlo simulations. As one of our main results we present numerical evidence that the susceptibility at the QCP seems to diverge with temperature T as chi ~ T^{-1.2} in the quantum case in contrast to the classical model where chi ~ T^{-4/3}.

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J. Sirker, V. Y. Krivnov, D. V. Dmitriev, A. Herzog, O. Janson, S. Nishimoto, S. -L. Drechsler, J. Richter. 2011-06-06. The J1-J2 Heisenberg model at and close to its z=4 quantum critical point. https://doi.org/10.1103/physrevb.84.144403

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