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Phase diagram of a Heisenberg spin-Peierls model with quantum phonons

Robert J. Bursill·Ross H. McKenzie·Chris J. Hamer
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Abstract

Using a new version of the density-matrix renormalization group we determine the phase diagram of a model of an antiferromagnetic Heisenberg spin chain where the spins interact with quantum phonons. A quantum phase transition from a gapless spin-fluid state to a gapped dimerized phase occurs at a non-zero value of the spin-phonon coupling. The transition is in the same universality class as that of a frustrated spin chain, which the model maps to in the anti-adiabatic limit. We argue that realistic modeling of known spin-Peierls materials should include the effects of quantum phonons.

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Robert J. Bursill, Ross H. McKenzie, Chris J. Hamer. 1999-05-31. Phase diagram of a Heisenberg spin-Peierls model with quantum phonons. https://doi.org/10.1103/physrevlett.83.408

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