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Helimagnetism in a disordered and geometrically frustrated quantum spin chain

T. Masuda·A. Zheludev·A. Bush·M. Markina·A. Vasiliev
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Abstract

Neutron diffraction and bulk measurements are used to determine the nature of the low-temperature ordered state in LiCu$_2$O$_2$, a $S=1/2$ spin-chain compound with competing interactions. The magnetic structure is found to be helimagnetic, with a propagation vector $(0.5,ζ,0)$, $ζ=0.174$. The nearest-neighbor exchange constant and frustration ratio are estimated to be $J=5.8$ meV and $J_2/J_1=0.29$, respectively. For idealized spin chains these parameter values would signify a gapped spin-liquid ground state. Long-range ordering is attributed to intrinsic non-stoichiometry.

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T. Masuda, A. Zheludev, A. Bush, M. Markina, A. Vasiliev. 2003-10-06. Helimagnetism in a disordered and geometrically frustrated quantum spin chain. https://arxiv.org/abs/cond-mat/0310126

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