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arXiv · 2306.17524

Silicene on Ag(111): an honeycomb lattice without Dirac bands

Sanjoy Kr. Mahatha·Paolo Moras·Valerio Bellini·Polina M. Sheverdyaeva·Claudia Struzzi·Luca Petaccia·Carlo Carbone
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Abstract

The discovery of (4x4) silicene formation on Ag(111) raised the question on whether silicene maintains its Dirac fermion character, similar to graphene, on a supporting substrate. Previous photoemission studies indicated that the {\pi}-band forms Dirac cones near the Fermi energy, while theoretical investigations found it shifted at deeper binding energy. By means of angle-resolved photoemission spectroscopy and density functional theory calculations we show instead that the {\pi}-symmetry states lose their local character and the Dirac cone fades out. The formation of an interface state of free-electron-like Ag origin is found to account for spectral features that were theoretically and experimentally attributed to silicene bands of {\pi}-character.

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Sanjoy Kr. Mahatha, Paolo Moras, Valerio Bellini, Polina M. Sheverdyaeva, Claudia Struzzi, Luca Petaccia, Carlo Carbone. 2023-06-30. Silicene on Ag(111): an honeycomb lattice without Dirac bands. https://doi.org/10.1103/physrevb.89.201416

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