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arXiv 2209.12964cond-mat.mes-hallcond-mat.str-el
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扭转三层石墨烯中的角度分辨输运非互易性与自发对称性破缺

Angle-resolved transport nonreciprocity and spontaneous symmetry breaking in twisted trilayer graphene

Naiyuan James Zhang, Jiang-Xiazi Lin, Dmitry V. Chichinadze, Yibang Wang, Kenji Watanabe, Takashi Taniguchi, Liang Fu, J. I. A. Li

AI总结:

本文通过角度分辨输运非互易性测量研究扭转三层石墨烯的自发对称性破缺,发现热循环和电流偏置诱导镜像轴滞回旋转,并揭示旋转对称性与时间反演对称性破缺的直接关联。

摘要:

识别和表征自发对称性破缺的能力对于我们理解具有强关联的二维材料至关重要,例如魔角扭转石墨烯双层和三层中的莫尔平带。在这项工作中,我们利用输运非互易性的角度分辨测量来研究扭转三层石墨烯中的自发对称性破缺。通过分析纵向和横向通道中非互易性的角度依赖性,我们能够确定与底层电子序相关的对称轴。我们报告称,热循环和大电流偏置可以诱导镜像轴发生滞回旋转,这为旋转对称性的自发破缺提供了明确的证据。此外,非互易性随温度降低而出现,与轨道铁磁性的出现同时发生。结合超导二极管效应的角度依赖性,我们的发现揭示了旋转对称性破缺与时间反演对称性破缺之间的直接联系。这些对称性要求指向动量空间中交换驱动的失稳,作为扭转三层石墨烯中输运非互易性的可能起源。

英文摘要:

The ability to identify and characterize spontaneous symmetry breaking is central to our understanding of 2D materials with strong correlation, such as the moiré flat bands in magic-angle twisted graphene bilayer and trilayer. In this work, we utilize angle-resolved measurements of transport nonreciprocity to investigate spontaneous symmetry breaking in twisted trilayer graphene. By analyzing the angular dependence of nonreciprocity in both longitudinal and transverse channels, we are able to identify the symmetry axis associated with the underlying electronic order. We report that a hysteretic rotation in the mirror axis can be induced by thermal cycles and a large current bias, which offers unambiguous evidence for the spontaneous breaking of rotational symmetry. Moreover, the onset of nonreciprocity with decreasing temperature coincides with the emergence of orbital ferromagnetism. Combined with the angular dependence of the superconducting diode effect, our findings uncover a direct link between rotational and time-reversal symmetry breaking. These symmetry requirements point towards the exchange-driven instabilities in the momentum space as a possible origin for transport nonreciprocity in tTLG.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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