Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 17: Symposium Quantum Magnetism in Molecule-based Materials
TT 17.5: Vortrag
Montag, 7. März 2005, 12:30–12:45, TU H104
Quantum sine-Gordon behaviour in copper pyrimidine dinitrate — •R. Feyerherm1, S. A. Zvyagin2, and A. U. B. Wolter3 — 1Hahn-Meitner-Institut, 14109 Berlin, Germany — 2NHFL, Florida State University, Tallahassee, FL 32310, U.S.A. — 3IMNF, TU Braunschweig, 38106 Braunschweig, Germany
Copper pyrimidine dinitrate has been recently identified as S = 1/2 antiferromagnetic chain with a field-induced spin gap [1], and turned out to be one of the best realizations of the quantum sine-Gordon spin chain model known to date. The field-induced gap arises from a perturbation from the isotropic Heisenberg chain by an alternating g-tensor and the Dzyaloshinskii-Moriya (DM) interaction. Other consequences of this perturbation are an intrinsic Curie-like contribution to the magnetic susceptibility [1], a large field-induced staggered magnetization perpendicular to the applied field [2], and a T−2 contribution to the ESR-linewidth [3]. Most interestingly, in recent high-field submillimeter wave ESR studies of the gapped state signatures of three breather branches and a soliton, besides several multi-particle excitations, have been identified and allowed for a detailed comparison with predictions from the quantum-sine Gordon field theory [4].
[1] R Feyerherm et. al., J. Phys.: Condens. Matter. 39 (2000) 8495
[2] A.U.B. Wolter et. al., Phys. Rev. B 68 (2003) 220406(R)
[3] T. Asaono et. al., Physica B 329-333 (2003) 1006
[4] S. A. Zvyagin et. al., Phys. Rev. Lett. 93 (2004) 027201