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Critical exponents of the quantum phase transition in a planar antiferromagnet

Matthias Troyer·Masatoshi Imada·Kazuo Ueda
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Abstract

We have performed a large scale quantum Monte Carlo study of the quantum phase transition in a planar spin-1/2 Heisenberg antiferromagnet with CaV4O9 structure. We obtain a dynamical exponent z=1.018+/-0.02. The critical exponents beta, nu and eta agree within our errors with the classical 3D O(3) exponents, expected from a mapping to the nonlinear sigma model. This confirms the conjecture of Chubukov, Sachdev and Ye [Phys. Rev. B 49, 11919 (1994)] that the Berry phase terms in the planar Heisenberg antiferromagnet are dangerously irrelevant.

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Matthias Troyer, Masatoshi Imada, Kazuo Ueda. 1997-02-12. Critical exponents of the quantum phase transition in a planar antiferromagnet. https://doi.org/10.1143/jpsj.66.2957

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