Fig. 2

a Li-ML band structure. The red patterns show the intensity of lithium σ bands. The blue dots show band structure obtained using σ-TBA model. b The ELF in Li-ML. The white dots show the upper edge \(\omega _ + = (Q^2 \pm 2k_FQ){\mathrm{/}}2m_{\sigma _1}^ \ast\) of intraband electron–hole continuum in parabolic (\(E_K = K^2{\mathrm{/}}2m_{\sigma _1}^ \ast\)) σ₁ band, where \(m_{\sigma _1}^ \ast = 1.15\) and corresponding Fermi wave vector is k_F = 0.285 a.u. The green dotted line shows the 2D plasmon dispersion relation for which only transitions within Li-ML σ₁ band are included. The blue dotted line shows the same 2D plasmon dispersion relation obtained within σ₁-TBA model. c The LiB₂N₂-ML band structure. Blue dots show the same as in a. d The ELF in LiB₂N₂-ML. The dispersion relations (11) in Li-ML (green dots), in Li + 2hBN model system (cyan squares) and in Li + 2hBN(LFE) model system (magenta circles). White dots show the same as in b