Evidence for a spinon Kondo effect in cobalt atoms on single-layer 1T-TaSe2
Evidence for a spinon Kondo effect in cobalt atoms on single-layer 1T-TaSe2
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DOI：
10.1038/s41567-022-01751-4
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发表时间：
2022-02
期刊：
影响因子：
19.6
通讯作者：
Yi Chen;Wenyan He;W. Ruan;Jinwoong Hwang;Shujie Tang;Ryan L. Lee;Meng Wu;T. Zhu;Canxun Zhang;H. Ryu;Feng Wang;S. Louie;Z. Shen;S. Mo;P. Lee;M. Crommie
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文献类型：
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作者：
Yi Chen;Wenyan He;W. Ruan;Jinwoong Hwang;Shujie Tang;Ryan L. Lee;Meng Wu;T. Zhu;Canxun Zhang;H. Ryu;Feng Wang;S. Louie;Z. Shen;S. Mo;P. Lee;M. Crommie
量子自旋液体是一种高度纠缠、无序的磁状态，预计将出现在受抑的莫特绝缘体中，并表现出奇异的分数激发，如自旋子和charcoons。尽管是电绝缘体，一些量子自旋液体被预测表现出无隙巡回自旋子，产生金属行为的电荷中性自旋通道。我们将孤立的磁性原子沉积到单层1 T-TaSe 2上，这是一种候选的无隙自旋液体，以探测巡游自旋子如何耦合到杂质自旋中心。使用扫描隧道光谱，我们观察到出现新的，杂质诱导的共振峰在1 T-TaSe 2 Hubbard带边时，钴吸附原子的位置，具有最大的空间重叠与当地的电荷分布。这些共振峰消失时，空间重叠减少，或当磁性杂质被取代的磁性杂质。修正的安德森杂质模型的理论模拟表明，所观察到的峰是一致的近藤共振结合自旋-电荷结合效应，由于出现规范场的波动引起的自旋子诱导。
Quantum spin liquids are highly entangled, disordered magnetic states that are expected to arise in frustrated Mott insulators and to exhibit exotic fractional excitations such as spinons and chargons. Despite being electrical insulators, some quantum spin liquids are predicted to exhibit gapless itinerant spinons that yield metallic behaviour in the charge-neutral spin channel. We deposited isolated magnetic atoms onto single-layer 1T-TaSe2, a candidate gapless spin liquid, to probe how itinerant spinons couple to impurity spin centres. Using scanning tunnelling spectroscopy, we observe the emergence of new, impurity-induced resonance peaks at the 1T-TaSe2Hubbard band edges when cobalt adatoms are positioned to have maximal spatial overlap with the local charge distribution. These resonance peaks disappear when the spatial overlap is reduced or when the magnetic impurities are replaced with nonmagnetic impurities. Theoretical simulations of a modified Anderson impurity model show that the observed peaks are consistent with a Kondo resonance induced by spinons combined with spin-charge binding effects that arise due to fluctuations of an emergent gauge field.