| Autor: |
Duming, Zhang, Jeonghoon, Ha, Hongwoo, Baek, Yang-Hao, Chan, Fabian D, Natterer, Alline F, Myers, Joshua D, Schumacher, William G, Cullen, Albert V, Davydov, Young, Kuk, M Y, Chou, Nikolai B, Zhitenev, Joseph A, Stroscio |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Physical review materials. 1(2) |
| ISSN: |
2475-9953 |
| Popis: |
We report a rectangular charge density wave (CDW) phase in strained 1T-VSe2 thin films synthesized by molecular beam epitaxy on c-sapphire substrates. The observed CDW structure exhibits an unconventional rectangular 4a×√3a periodicity, as opposed to the previously reported hexagonal 4a×4a structure in bulk crystals and exfoliated thin layered samples. Tunneling spectroscopy shows a strong modulation of the local density of states of the same 4a×√3a CDW periodicity and an energy gap of 2ΔCDW = (9.1 ± 0.1) meV. The CDW energy gap evolves into a full gap at temperatures below 500 mK, indicating a transition to an insulating phase at ultra-low temperatures. First-principles calculations confirm the stability of both 4a×4a and 4a×√3a structures arising from soft modes in the phonon dispersion. The unconventional structure becomes preferred in the presence of strain, in agreement with experimental findings. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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