The Quasi-1D S=1/2 Antiferromagnet Cs2CuCl4 in a Magnetic Field
نویسندگان
چکیده
Magnetic excitations of the quasi-1D S = 1/2 Heisenberg antiferromagnet (HAF) Cs2CuCl4 have been measured as a function of magnetic field using neutron scattering. For T < 0.62 K and B=0 T the weak inter-chain coupling produces 3D incommensurate ordering. Fields greater than BC =1.66 T, but less than the field ( ≃ 8 T) required to fully align the spins, are observed to decouple the chains, and the system enters a disordered intermediate-field phase (IFP). The IFP excitations are in agreement with the predictions of Müller et al. for the 1D S = 1/2 HAF, and Talstra and Haldane for the related 1/r chain (the Haldane-Shastry model). This behaviour is inconsistent with linear spin-wave theory. 75.10.Jm, 75.10.Hk, 75.30.Ds Typeset using REVTEX
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