Table 1 The lattice constant a, bond length d1 (d2) between the central-layer atom and the up-layer (low-layer) atom, charge transfer ΔQ1 (ΔQ2) from the central-layer atom to the up-layer (low-layer) atom, cohensive energy Ecoh, band gap Eg, electronic states (including normal insulating (NI), metallic (M), and TI), and dynamic stability for the trigonal poloniumene ML with X (X = S, Se, Te) atoms doped. The SOC is considered.
From: Trigonal multivalent polonium monolayers with intrinsic quantum spin Hall effects
Pattern | Atom | a(Å) | d1(Å) | d2(Å) | ΔQ1 | ΔQ2 | Ecoh(eV/atom) | Eg(eV) | State | Stable |
|---|---|---|---|---|---|---|---|---|---|---|
XPoPo | S | 4.21 | 2.815 | 3.221 | 0.64 | 0.16 | 3.172 | 0.37 | TI | Y |
Se | 4.28 | 2.945 | 3.231 | 0.49 | 0.16 | 3.074 | 0.30 | TI | Y | |
Te | 4.41 | 3.152 | 3.245 | 0.29 | 0.16 | 2.989 | 0.19 | TI | Y | |
PoXPo | S | 3.92 | 2.954 | 2.954 | − 0.30 | − 0.31 | 3.028 | 0.00 | M | N |
Se | 4.11 | 3.036 | 3.036 | − 0.16 | − 0.16 | 2.975 | 0.00 | TI | Y | |
Te | 4.36 | 3.185 | 3.185 | 0.02 | 0.02 | 2.970 | 0.37 | TI | Y | |
XPoX | S | 3.96 | 2.778 | 2.778 | 0.65 | 0.65 | 3.185 | 0.63 | NI | Y |
Se | 4.11 | 2.918 | 2.918 | 0.50 | 0.50 | 2.954 | 0.46 | NI | Y | |
Te | 4.36 | 3.135 | 3.135 | 0.30 | 0.30 | 2.750 | 0.16 | NI | Y | |
XXPo | S | 3.75 | 2.495 | 2.839 | 0.18 | − 0.28 | 2.721 | 0.19 | NI | N |
Se | 3.98 | 2.722 | 2.969 | 0.18 | − 0.14 | 2.689 | 0.07 | NI | N | |
Te | 4.32 | 3.071 | 3.163 | 0.17 | 0.05 | 2.693 | 0.03 | TI | Y |
