The pure Kitaev honeycomb model harbors a quantum spin liquid in zero magnetic fields, while applying finite magnetic fields induces a topological spin liquid with non-Abelian anyonic excitations. This latter phase has been much sought after in Kitaev candidate materials, such as α-RuCl₃. Currently, two competing scenarios exist for the intermediate field phase of this compound (B = 7 − 10 T), based on experimental as well as theoretical results: (i) conventional multiparticle magnetic excitations of integer quantum number vs. (ii) Majorana fermionic excitations of possibly non-Abelian nature with a fractional quantum number. To discriminate between these scenarios a detailed investigation of excitations over a wide field-temperature phase diagram is essential. Here, we present Raman spectroscopic data revealing low-energy quasiparticles emerging out of a continuum of fractionalized excitations at intermediate fields, which are contrasted by conventional spin-wave excitations. The temperature evolution of these quasiparticles suggests the formation of bound states out of fractionalized excitations.

纯Kitaev蜂窝模型在零磁场中包含量子自旋液体，而施加有限磁场会诱发具有非阿贝尔非离子激发的拓扑自旋液体。在Kitaev候选材料（例如α- RuCl _3）中已经非常追求后一个阶段。目前，该化合物的中场阶段存在两种竞争场景（B = 7-10 T），基于实验和理论结果：（i）整数量子数与（ii）可能具有分数量子数的非阿贝尔性质的马约拉纳铁氧体激发。为了区分这些情况，必须对宽场温度相图上的激励进行详细研究。在这里，我们提供拉曼光谱数据，揭示低能量的准粒子出现在中间场的连续分馏激发中，这与传统的自旋波激发形成了对比。这些准粒子的温度演变表明，在分步激发作用下会形成结合态。