Odd-even layer-number effect of valence-band spin splitting in WTe_{2}

When a crystal becomes thin to the atomic level, peculiar phenomena discretely depending on its layer numbers (n) start to appear. Here, we investigate the electronic band dispersions of multilayer WTe_{2} (2–5 layers), by performing laser-based microfocused angle-resolved photoelectron spectroscopy...

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Bibliographic Details
Main Authors: Masato Sakano, Yuma Tanaka, Satoru Masubuchi, Shota Okazaki, Takuya Nomoto, Atsushi Oshima, Kenji Watanabe, Takashi Taniguchi, Ryotaro Arita, Takao Sasagawa, Tomoki Machida, Kyoko Ishizaka
Format: Article
Language:English
Published: American Physical Society 2022-06-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.4.023247
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Summary:When a crystal becomes thin to the atomic level, peculiar phenomena discretely depending on its layer numbers (n) start to appear. Here, we investigate the electronic band dispersions of multilayer WTe_{2} (2–5 layers), by performing laser-based microfocused angle-resolved photoelectron spectroscopy on exfoliated flakes sorted by n. We observe that the holelike valence bands start to cross the Fermi level when the number of layers is increased from 2- to 3 layers, which should be related to the insulator-semimetal transition, as well as the 30–70-meV spin splitting of valence bands manifesting in even n as a signature of stronger structural asymmetry. Our result fully demonstrates the possibility of the large energy-scale band and spin manipulation through the finite-n stacking procedure.
ISSN:2643-1564