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Phase diagram of the random Heisenberg antiferromagnetic spin-1 chain

A. Saguia·B. Boechat·M. A. Continentino
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Abstract

We present a new perturbative real space renormalization group (RG) to study random quantum spin chains and other one-dimensional disordered quantum systems. The method overcomes problems of the original approach which fails for quantum random chains with spins larger than S=1/2. Since it works even for weak disorder we are able to obtain the zero temperature phase diagram of the random antiferromagnetic Heisenberg spin-1 chain as a function of disorder. We find a random singlet phase for strong disorder and as disorder decreases, the system shows a crossover from a Griffiths to a disordered Haldane phase.

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A. Saguia, B. Boechat, M. A. Continentino. 2002-05-23. Phase diagram of the random Heisenberg antiferromagnetic spin-1 chain. https://doi.org/10.1103/physrevlett.89.117202

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