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arXiv · 1412.2411

Giant magnetic-field dependence of the coupling between spin Tomonaga-Luttinger liquids in BaCo2V2O8

M. Klanjsek·M. Horvatic·S. Kramer·S. Mukhopadhyay·H. Mayaffre·C. Berthier·E. Canevet·B. Grenier·P. Lejay·E. Orignac
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Abstract

We use nuclear magnetic resonance to map the complete low-temperature phase diagram of the antiferromagnetic Ising-like spin-chain system BaCo2V2O8 as a function of the magnetic field applied along the chains. In contrast to the predicted crossover from the longitudinal incommensurate phase to the transverse antiferromagnetic phase, we find a sequence of three magnetically ordered phases between the critical fields 3.8 T and 22.8 T. Their origin is traced to the giant magnetic-field dependence of the total effective coupling between spin chains, extracted to vary by a factor of 24. We explain this novel phenomenon as emerging from the combination of nontrivially coupled spin chains and incommensurate spin fluctuations in the chains treated as Tomonaga-Luttinger liquids.

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M. Klanjsek, M. Horvatic, S. Kramer, S. Mukhopadhyay, H. Mayaffre, C. Berthier, E. Canevet, B. Grenier, P. Lejay, E. Orignac. 2014-12-07. Giant magnetic-field dependence of the coupling between spin Tomonaga-Luttinger liquids in BaCo2V2O8. https://doi.org/10.1103/physrevb.92.060408

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