Garlea, V.O.; Zheludev, A.; Regnault, L.-P.; Chung, J.-H.; Qiu, Y.; Boehm, M.; Habicht, K.; Meissner, M.: Excitations in a four-leg antiferromagnetic Heisenberg spin tube. Physical Review Letters 100 (2008), p. 037206/1-4
10.1103/PhysRevLett.100.037206
Open Access Version
Abstract:
Inelastic neutron scattering is used to investigate magnetic excitations in the quasi-one-dimensional quantum spin-liquid system Cu2Cl4 D8C4SO2. Contrary to previously conjectured models that relied on bond-alternating nearest-neighbor interactions in the spin chains, the dominant interactions are actually next-nearest-neighbor in-chain antiferromagnetic couplings. The appropriate Heisenberg Hamiltonian is equivalent to that of a S 1=/2 4-leg spin-tube with almost perfect one dimensionality and no bond alternation. A partial geometric frustration of rung interactions induces a small incommensurability of short-range spin correlations.