扭曲双层PtTe2中的杂化控制再入电子相切换和莫尔限制态
Hybridization-controlled re-entrant electronic phase switching and moire-confined states in twisted bilayer PtTe2
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中文总结 AI 辅助
研究扭曲双层PtTe₂中电子态演化，通过第一性原理计算发现其在无隙和有隙态间非单调变化，7.34°结构无隙，中间角度有能隙，60°构型能隙关闭更大角度重新打开，确定层间杂化重新分布是再入能隙演化微观起源。
中文摘要 AI 辅助
扭曲范德华双层不仅会改变莫尔周期性，还会改变局部堆叠和层间杂化。本文通过包括自旋轨道耦合、能带展开和布里渊区积分态密度的完全弛豫第一性原理计算表明，双层PtTe₂在无隙和有隙电子态之间呈现非单调演化。7.34°结构保持无隙，而在采样的中间角度出现有限的直接能隙。能隙在采样的60°构型处关闭，并在更大角度重新打开。直接能隙总体上随最小局部层间Pt - Pt间距增加，不过需要完整的局部堆叠环境分布来解释与该趋势的偏差。在7.34°时，低能态主要集中在原本无隙的莫尔晶胞的AA类区域。控制层间距扫描表明，增加层间距会消除近费米能级交叉并打开能隙，这与层间Te - pz杂化减弱一致。这些结果确定了层间杂化的重新分布是扭曲双层PtTe₂中再入能隙演化的微观起源。
英文摘要
Twisting a van der Waals bilayer changes not only the moiré 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 moiré 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$_2$.
