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High Magnetic Field ESR in the Haldane Spin Chains NENP and NINO

M. Sieling·U. Löw·B. Wolf·S. Schmidt·S. Zvyagin·B. Lüthi
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Abstract

We present electron spin resonance experiments in the one-dimensional antiferromagnetic S=1 spin chains NENP and NINO in pulsed magnetic fields up to 50T. The measured field dependence of the quantum energy gap for B||b is analyzed using the exact diagonalization method and the density matrix renormalization group method (DMRG). A staggered anisotropy term (-1)^i d(S_i^x S_i^z + S_i^z S_i^x) was considered for the first time in addition to a staggered field term (-1)^i S_i^x B_st. We show that the spin dynamics in high magnetic fields strongly depends on the orthorhombic anisotropy E.

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M. Sieling, U. Löw, B. Wolf, S. Schmidt, S. Zvyagin, B. Lüthi. 1999-06-17. High Magnetic Field ESR in the Haldane Spin Chains NENP and NINO. https://doi.org/10.1103/physrevb.61.88

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