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arXiv · 2205.13126

Observation of a multitude of correlated states at the surface of bulk 1T-TaSe$_2$ crystals

Yi Chen·Wei Ruan·Jeffrey D. Cain·Ryan L. Lee·Salman Kahn·Caihong Jia·Alex Zettl·Michael F. Crommie
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Abstract

The interplay between electron-electron interactions and structural ordering can yield exceptionally rich correlated electronic phases. We have used scanning tunneling microscopy to investigate bulk 1T-TaSe2 and have uncovered surprisingly diverse correlated surface states thereof. These surface states exhibit the same in-plane charge density wave ordering but dramatically different electronic ground states ranging from insulating to metallic. The insulating variety of surface state shows signatures of a decoupled surface Mott layer. The metallic surface states, on the other hand, exhibit zero-bias peaks of varying strength that suggest Kondo phases arising from coupling between the Mott surface layer and the metallic bulk of 1T-TaSe2. The surface of bulk 1T-TaSe2 thus constitutes a rare realization of the periodic Anderson model covering a wide parameter regime, thereby providing a model system for accessing different correlated phenomena in the same crystal. Our results highlight the central role played by strong correlations in this material family.

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Yi Chen, Wei Ruan, Jeffrey D. Cain, Ryan L. Lee, Salman Kahn, Caihong Jia, Alex Zettl, Michael F. Crommie. 2022-09-05. Observation of a multitude of correlated states at the surface of bulk 1T-TaSe$_2$ crystals. https://doi.org/10.1103/physrevb.106.075153

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