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arXiv · 2006.13743

Magnetic order and ballistic spin transport in a sine-Gordon spin chain

B. M. Huddart·M. Gomilšek·T. J. Hicken·F. L. Pratt·S. J. Blundell·P. A. Goddard·S. J. Kaech·J. L. Manson·T. Lancaster
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Abstract

We report the results of muon-spin spectroscopy ($\mu^+$SR) measurements on the staggered molecular spin chain [pym-Cu(NO$_3$)$_2$(H$_2$O)$_2$] (pym = pyrimidine), a material previously described using sine-Gordon field theory. Zero-field $\mu^+$SR reveals a long range magnetically-ordered ground state below a transition temperature $T_\mathrm{N}=0.22(1)$ K. Using longitudinal-field (LF) $\mu^+$SR we investigate the dynamic response in applied magnetic fields $0< B < 500$ mT and find evidence for ballistic spin transport. Our LF $\mu^+$SR measurements on the chiral spin chain [Cu(pym)(H$_2$O)$_4$]SiF$_6 \cdot $H$_2$O instead demonstrate one-dimensional spin diffusion and the distinct spin transport in these two systems likely reflects differences in their magnetic excitations.

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B. M. Huddart, M. Gomilšek, T. J. Hicken, F. L. Pratt, S. J. Blundell, P. A. Goddard, S. J. Kaech, J. L. Manson, T. Lancaster. 2020-06-24. Magnetic order and ballistic spin transport in a sine-Gordon spin chain. https://doi.org/10.1103/physrevb.103.l060405

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