| Emergence of a Metal-Insulator Transition and High-Temperature Charge-Density Waves in VSe2 at the Monolayer Limit | |||||
| 작성자 | 김** | 작성일 | 2019-07-29 | 조회수 | 100 |
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Journal Article published 12 Sep 2018 in Nano Letters volume 18 issue 9 on pages 5432 to 5438
Research funded by National Research Foundation of Korea (NRF-2015R1D1A1A01057271NRF-2009-0093818NRF-2014R1A4A1071686NRF-2015R1C1A1A01051629NRF-2017R1C1B20049272011-0030046) | Natur og Univers, Det Frie Forskningsrad (DFF-4090-00125) | Villum Fonden (15375) | Institute for Basic Science (IBS-R009-G1) | Basic Science Research Institute, Pohang University of Science and Technology
Abstract Emergent phenomena driven by electronic reconstructions in oxide heterostructures have been intensively discussed. However, the role of these phenomena in shaping the electronic properties in van der Waals heterointerfaces has hitherto not been established. By reducing the material thickness and forming a heterointerface, we find two types of charge-ordering transitions in monolayer VSe2 on graphene substrates. Angle-resolved photoemission spectroscopy (ARPES) uncovers that Fermi-surface nesting becomes perfect in ML VSe2. Renormalization-group analysis confirms that imperfect nesting in three dimensions universally flows into perfect nesting in two dimensions. As a result, the charge-density wave-transition temperature is dramatically enhanced to a value of 350 K compared to the 105 K in bulk VSe2. More interestingly, ARPES and scanning tunneling microscopy measurements confirm an unexpected metal?insulator transition at 135 K that is driven by lattice distortions. The heterointerface plays an important role in driving this novel metal?insulator transition in the family of monolayer transition-metal dichalcogenides. |
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