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Spin Reduction Transition in Spin-3/2 Random Heisenberg Chains

Gil Refael·Stefan Kehrein·Daniel S. Fisher
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Abstract

Random spin-3/2 antiferromagnetic Heisenberg chains are investigated using an asymptotically exact renormalization group. Randomness is found to induce a quantum phase transition between two random-singlet phases. In the strong randomness phase the effective spins at low energies are S_eff=3/2, while in the weak randomness phase the effective spins are S_eff=1/2. Separating them is a quantum critical point near which there is a non-trivial mixture of S=1/2, S=1, and S=3/2 effective spins at low temperatures.

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Gil Refael, Stefan Kehrein, Daniel S. Fisher. 2002-08-23. Spin Reduction Transition in Spin-3/2 Random Heisenberg Chains. https://doi.org/10.1103/physrevb.66.060402

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