Helimagnetism in a disordered and geometrically frustrated quantum spin chain

T. Masuda; A. Zheludev; A. Bush; M. Markina; A. Vasiliev

paper

Helimagnetism in a disordered and geometrically frustrated quantum spin chain

arXiv:cond-mat/0310126

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.

4 pages 4 figures