Gnezdilov, V.; Kurnosov, V.; Pashkevich, Y.; Bera, A.K.; Islam, A.T.M.N.; Lake, B.; Lobbenmeier, B.; Wulferding, D.; Lemmens, P.: Non-Abelian statistics in light-scattering processes across interacting Haldane chains. Physical Review B 104 (2021), p. 165118/1-8
10.1103/physrevb.104.165118
Open Access Version
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 archetype, the quasi-one-dimensional SrNi2V2O8 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 ΔH and the exchange coupling Jc 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 fermionic statistics. Such statistics has also been observed in Kitaev spin liquids and could point to a non-Abelian symmetry. As the ground state in the bulk of SrNi2V2O8 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 SrCo2V2O8, the S=1/2 analog to our title compound, supports these statements.