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Ground state of the random-bond spin-1 Heisenberg chain

Sara Bergkvist·Patrik Henelius·Anders Rosengren
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Abstract

Stochastic series expansion quantum Monte Carlo is used to study the ground state of the antiferromagnetic spin-1 Heisenberg chain with bond disorder. Typical spin- and string-correlations functions behave in accordance with real-space renormalization group predictions for the random-singlet phase. The average string-correlation function decays algebraically with an exponent of -0.378(6), in very good agreement with the prediction of $-(3-\sqrt{5})/2\simeq -0.382$, while the average spin-correlation function is found to decay with an exponent of about -1, quite different from the expected value of -2. By implementing the concept of directed loops for the spin-1 chain we show that autocorrelation times can be reduced by up to two orders of magnitude.

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Sara Bergkvist, Patrik Henelius, Anders Rosengren. 2002-06-06. Ground state of the random-bond spin-1 Heisenberg chain. https://doi.org/10.1103/physrevb.66.134407

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