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Structure of end states for a Haldane Spin Chain

M. Kenzelmann·G. Xu·I. A. Zaliznyak·C. Broholm·J. F. DiTusa·G. Aeppli·T. Ito·K. Oka·H. Takagi
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Abstract

Inelastic neutron scattering was used to probe edge states in a quantum spin liquid. The experiment was performed on finite length antiferromagnetic spin-1 chains in Y_2BaNi_{1-x}Mg_xO_5. At finite fields, there is a Zeeman resonance below the Haldane gap. The wave vector dependence of its intensity provides direct evidence for staggered magnetization at chain ends, which decays exponentially towards the bulk (xi = 8(1) at T=0.1K). Continuum contributions to the chain end spectrum indicate inter-chain-segment interactions. We also observe a finite size blue shift of the Haldane gap.

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M. Kenzelmann, G. Xu, I. A. Zaliznyak, C. Broholm, J. F. DiTusa, G. Aeppli, T. Ito, K. Oka, H. Takagi. 2002-11-29. Structure of end states for a Haldane Spin Chain. https://doi.org/10.1103/physrevlett.90.087202

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