Imaging orbital ferromagnetism in a moiré Chern insulator

doi:10.1126/science.abd3190

GSTDTAP > 气候变化

DOI	10.1126/science.abd3190
	Imaging orbital ferromagnetism in a moiré Chern insulator
	C. L. Tschirhart; M. Serlin; H. Polshyn; A. Shragai; Z. Xia; J. Zhu; Y. Zhang; K. Watanabe; T. Taniguchi; M. E. Huber; A. F. Young
	2021-06-18
发表期刊	Science
出版年	2021
英文摘要	Ferromagnetism is associated with the breaking of time-reversal symmetry, most frequently by the spin degree of freedom. Although the orbital motion of electrons can also contribute to ferromagnetism, in most materials, it is small relative to the spin contribution. Tschirhart et al. showed that the reverse is true in an unusual magnetic state hosted by twisted bilayer graphene. Their scanning magnetometry measurements were consistent with ferromagnetism of predominantly orbital origin. Science , abd3190, this issue p. [1323][1] Electrons in moiré flat band systems can spontaneously break time-reversal symmetry, giving rise to a quantized anomalous Hall effect. In this study, we use a superconducting quantum interference device to image stray magnetic fields in twisted bilayer graphene aligned to hexagonal boron nitride. We find a magnetization of several Bohr magnetons per charge carrier, demonstrating that the magnetism is primarily orbital in nature. Our measurements reveal a large change in the magnetization as the chemical potential is swept across the quantum anomalous Hall gap, consistent with the expected contribution of chiral edge states to the magnetization of an orbital Chern insulator. Mapping the spatial evolution of field-driven magnetic reversal, we find a series of reproducible micrometer-scale domains pinned to structural disorder. [1]: /lookup/doi/10.1126/science.abd3190
领域	气候变化 ; 资源环境
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/330810
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	C. L. Tschirhart,M. Serlin,H. Polshyn,et al. Imaging orbital ferromagnetism in a moiré Chern insulator[J]. Science,2021.
APA	C. L. Tschirhart.,M. Serlin.,H. Polshyn.,A. Shragai.,Z. Xia.,...&A. F. Young.(2021).Imaging orbital ferromagnetism in a moiré Chern insulator.Science.
MLA	C. L. Tschirhart,et al."Imaging orbital ferromagnetism in a moiré Chern insulator".Science (2021).