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Quantum phase transition in easy-axis antiferromagnetic integer-spin chains

M. Capone·S. Caprara·L. Cataldi
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Abstract

Antiferromagnetic Heisenberg integer-spin chains are characterized by a spin-liquid ground state with no long-range order, due to the relevance of quantum fluctuations. Spin anisotropy, however, freezes quantum fluctuations, and the system is magnetized in the presence of a sufficiently large easy-axis anisotropy. We numerically investigate the case S=1, by means of the density-matrix renormalization group, and find that the freezing of the spin liquid into a Néel spin solid, with increasing easy-axis anisotropy, is a continuous quantum phase transition. Numerical evidence indicates that the transition is not in the two-dimensional Ising universality class.

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M. Capone, S. Caprara, L. Cataldi. 2003-07-11. Quantum phase transition in easy-axis antiferromagnetic integer-spin chains. https://arxiv.org/abs/cond-mat/0307266

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