Probing signatures of fractionalization in the candidate quantum spin liquid Cu2IrO3 via anomalous Raman scattering
Probing signatures of fractionalization in the candidate quantum spin liquid Cu2IrO3 via anomalous Raman scattering
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DOI：
10.1103/physrevb.104.184420
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发表时间：
2021-11-17
影响因子：
3.7
通讯作者：
Sood, A. K.
中科院分区：
文献类型：
--
作者：
Pal, Srishti;Seth, Arnab;Sood, A. K.
量子自旋液体（QSL）中的长程纠缠导致了具有分数量子数和（二维）统计的新型低能激发。这些激励的实验检测和操纵提出了挑战，特别是在不同的候选磁体。它们与声子的耦合是一个很有前途的研究分馏的探针。在这里，我们提出了拉曼散射的结果为S = 1/2蜂窝状铱酸铜2 IrO 3，一个候选Kitaev QSL与细分马约拉纳费米子和伊辛通量激发。我们观察到异常的低温频移和线宽展宽的拉曼强度除了一个广泛的磁连续，这两个，因为我们推导出，自然是由于声子衰减到巡回马约拉纳。动态拉曼磁化率标志着在120 K附近从QSL到热顺磁体的一个交叉。低于此温度的声子异常表现出强烈的声子-马约拉纳耦合。这些结果为Cu 2 IrO 3的自旋分馏提供了证据。
Long-range entanglement in quantum spin liquids (QSLs) leads to novel low-energy excitations with fractionalized quantum numbers and (in two dimensions) statistics. Experimental detection and manipulation of these excitations present a challenge particularly in view of diverse candidate magnets. A promising probe of fractionalization is their coupling to phonons. Here, we present Raman scattering results for the S = 1/2 honeycomb iridate Cu2IrO3, a candidate Kitaev QSL with fractionalized Majorana fermions and Ising flux excitations. We observe anomalous low-temperature frequency shift and linewidth broadening of the Raman intensities in addition to a broad magnetic continuum, both of which, as we derive, are naturally attributed to the phonon decaying into itinerant Majoranas. The dynamic Raman susceptibility marks a crossover from the QSL to a thermal paramagnet at similar to 120 K. The phonon anomalies below this temperature demonstrate a strong phonon-Majorana coupling. These results provide evidence of spin fractionalization in Cu2IrO3.