Doped coupled frustrated spin-1/2 chains with four-spin exchange.
The role of various magnetic interchain couplings is investigated by numerical methods in doped frustrated quantum spin chains. A nonmagnetic dopant introduced in a gapped spin chain releases a free spin-1/2 soliton. The formation of a local magnetic moment is analyzed in terms of soliton confinement. A four-spin coupling which might originate from cyclic exchange is shown to produce such a confinement. Dopants on different chains experience an effective space-extended nonfrustrating pairwise spin interaction.
Laflorencie
Nicolas
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Laboratoire de Physique Théorique CNRS-FRE2603, Université Paul Sabatier, F-31062 Toulouse, France.
Poilblanc
Didier
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