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arXiv · 0708.4181

Spin-Peierls instability in the three-leg Heisenberg ladder

Mohamed Azzouz·Khalada Shahin·Gennady Y. Chitov
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Abstract

Because the three-leg ladder behaves like a renormalized single Heisenberg chain we argue that a spin-Peierls instability must occur in this system when it is coupled to three-dimensional phonons. Using the bond-mean-field theory, we show that this is indeed the case. The dimerized state below the spin-Peierls transition temperature forms into the columnar dimerized phase not the staggered one. This contrasts with the argument based on antiferromagnetism. A physical argument based rather on spin bonding into singlets explains why the columnar configuration is favored. No quantum criticality (gaplessness) can occur in the columnar arrangement of the dimerized chains.

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Mohamed Azzouz, Khalada Shahin, Gennady Y. Chitov. 2007-08-30. Spin-Peierls instability in the three-leg Heisenberg ladder. https://doi.org/10.1103/physrevb.76.132410

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