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arXiv · 2106.08651

Non-Abelian statistics in light scattering processes across interacting Haldane chains

Vladimir Gnezdilov·Vladimir Kurnosov·Yurii Pashkevich·Anup Kumar Bera·A. T. M. Nazmul Islam·Bella Lake·Bodo Lobbenmeier·Dirk Wulferding·Peter Lemmens
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Abstract

The $S=1$ Haldane state is constructed from a product of local singlet dimers in the bulk and topological states at the edges of a chain. It is a fundamental representative of topological quantum matter. Its well-known representative, the quasi-one-dimensional SrNi$_2$V$_2$O$_8$ shows both conventional as well as unconventional magnetic Raman scattering. The former is observed as one- and two-triplet excitations with small linewidths and energies corresponding to the Haldane gap $Δ_H$ and the exchange coupling $J_c$ along the chain, respectively. Well-defined magnetic quasiparticles are assumed to be stabilized by interchain interactions and uniaxial single-ion anisotropy. Unconventional scattering exists as broad continua of scattering with an intensity $I(T)$ that shows a mixed bosonic / fermionic statistic. Such a mixed statistic has also been observed in Kitaev spin liquids and could point to a non-Abelian symmetry. As the ground state in the bulk of SrNi$_2$V$_2$O$_8$ is topologically trivial, we suggest its fractionalization to be due to light-induced interchain exchange processes. These processes are supposed to be enhanced due to a proximity to an Ising ordered state with a quantum critical point. A comparison with SrCo$_2$V$_2$O$_8$, the $S=1/2$ analogue to our title compound, supports these statements.

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Vladimir Gnezdilov, Vladimir Kurnosov, Yurii Pashkevich, Anup Kumar Bera, A. T. M. Nazmul Islam, Bella Lake, Bodo Lobbenmeier, Dirk Wulferding, Peter Lemmens. 2021-06-16. Non-Abelian statistics in light scattering processes across interacting Haldane chains. https://doi.org/10.1103/physrevb.104.165118

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