TY - JOUR
T1 - Spin excitations in an anisotropic bond-alternating quantum S=1 chain in a magnetic field
T2 - Contrast to Haldane spin chains
AU - Hagiwara, M.
AU - Regnault, L. P.
AU - Zheludev, A.
AU - Stunault, A.
AU - Metoki, N.
AU - Suzuki, T.
AU - Suga, S.
AU - Kakurai, K.
AU - Koike, Y.
AU - Vorderwisch, P.
AU - Chung, J. H.
PY - 2005/5/6
Y1 - 2005/5/6
N2 - Inelastic neutron scattering experiments on the S=1 quasi-one-dimensional bond-alternating antiferromagnet Ni(C9D24N4)(NO2)ClO4 have been performed under magnetic fields below and above a critical field Hc at which the energy gap closes. Normal field dependence of Zeeman splitting of the excited triplet modes below Hc has been observed, but the highest mode is unusually small and smears out with increasing field. This can be explained by an interaction with a low-lying two magnon continuum at q=π that is present in dimerized chains but absent in uniform ones. Above Hc, we find only one excited mode, in stark contrast with three massive excitations previously observed in the structurally similar Haldane-gap material NDMAP [A. Zheludev, Phys. Rev. BPRBMDO0163-1829 68, 134438 (2003)10.1103/PhysRevB.68.134438].
AB - Inelastic neutron scattering experiments on the S=1 quasi-one-dimensional bond-alternating antiferromagnet Ni(C9D24N4)(NO2)ClO4 have been performed under magnetic fields below and above a critical field Hc at which the energy gap closes. Normal field dependence of Zeeman splitting of the excited triplet modes below Hc has been observed, but the highest mode is unusually small and smears out with increasing field. This can be explained by an interaction with a low-lying two magnon continuum at q=π that is present in dimerized chains but absent in uniform ones. Above Hc, we find only one excited mode, in stark contrast with three massive excitations previously observed in the structurally similar Haldane-gap material NDMAP [A. Zheludev, Phys. Rev. BPRBMDO0163-1829 68, 134438 (2003)10.1103/PhysRevB.68.134438].
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U2 - 10.1103/PhysRevLett.94.177202
DO - 10.1103/PhysRevLett.94.177202
M3 - Article
AN - SCOPUS:27144433557
VL - 94
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 17
M1 - 177202
ER -