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arXiv · 2607.13529

Hybridization-controlled re-entrant electronic phase switching and moire-confined states in twisted bilayer PtTe2

Seoung-Hun Kang·Jeonghwan Ahn·Young-Kyun Kwon
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Abstract

Twisting a van der Waals bilayer changes not only the moir\'e periodicity but also the local stacking and interlayer hybridization. Here, we show, using fully relaxed first-principles calculations including spin--orbit coupling, band unfolding, and Brillouin-zone-integrated densities of states, that bilayer PtTe$_2$ exhibits a non-monotonic evolution between gapless and gapped electronic regimes. The $7.34^\circ$ structure remains gapless, whereas finite direct gaps appear at the sampled intermediate angles. The gap closes at the sampled $60^\circ$ configuration and reopens at higher angles. The direct gap shows an overall increase with the minimum local interlayer Pt--Pt separation, although the complete distribution of local stacking environments is required to account for deviations from this trend. At $7.34^\circ$, the low-energy states are concentrated predominantly in the AA-like regions of the otherwise gapless moir\'e cell. Controlled interlayer-separation scans show that increasing the layer spacing removes the near-$E_F$ crossings and opens a gap, consistent with weakened interlayer Te-$p_z$ hybridization. These results identify the redistribution of interlayer hybridization as the microscopic origin of the re-entrant gap evolution in twisted bilayer PtTe$_2$.

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Seoung-Hun Kang, Jeonghwan Ahn, Young-Kyun Kwon. 2026-07-15. Hybridization-controlled re-entrant electronic phase switching and moire-confined states in twisted bilayer PtTe2. https://arxiv.org/abs/2607.13529

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