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Strongly reduced gap in the zigzag spin chain with a ferromagnetic interchain coupling

Chigak Itoi·Shaojin Qin
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Abstract

We study a spin 1/2 Heisenberg zigzag spin chain model near decoupled two chains. Taking into account a symmetry breaking perturbation, we discuss the existence of an energy gap in the ferromagnetic interchain coupling as well as the antiferromagnetic one. In the ferromagnetic model, a marginally relevant fixed line reduces the gap strongly, so that the correlation length becomes an astronomical length scale even in order 1 coupling. This result agrees with density matrix renormalization group results.

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Chigak Itoi, Shaojin Qin. 2001-02-14. Strongly reduced gap in the zigzag spin chain with a ferromagnetic interchain coupling. https://doi.org/10.1103/physrevb.63.224423

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