Numerical study of critical properties and hidden orders in dimerized spin ladders

Dimerized antiferromagnetic spin-1/2 ladders are known to exhibit a quantum critical phase transition in the ground state, the existence or absence of which is dependent on the dimerization pattern of the ladder. The gapped phases cannot be distinguished by the conventional Landau long-range order p...

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Bibliographic Details
Published in:arXiv.org 2011-03
Main Authors: Gibson, S J, Meyer, R, Chitov, G Y
Format: Article
Language:English
Subjects:
Antiferromagnetism
Dimerization
Energy gap
Ground state
Ladders
Long range order
Order parameters
Phase transitions
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Summary:Dimerized antiferromagnetic spin-1/2 ladders are known to exhibit a quantum critical phase transition in the ground state, the existence or absence of which is dependent on the dimerization pattern of the ladder. The gapped phases cannot be distinguished by the conventional Landau long-range order parameter. However, they possess a non-local (hidden) string order parameter, which is non-zero in one phase and vanishes in the other. We use an exact diagonalization technique to calculate ground state energies, energy gaps and string order parameters of dimerized two- and three-leg Heisenberg ladders, as well as a critical scaling analysis to yield estimates of the critical exponents nu and beta.
ISSN:2331-8422
DOI:10.48550/arxiv.1009.5393