Tunable Topological States in Electron-Doped HTT-Pt

Abstract

Driving existing materials to exhibit topologically nontrivial state is of both scientific and technological interests. Using first-principle calculations, we propose the first demonstration of electron doping induced multiple quantum phase transition in a single material of the organometallic framework, HTT-Pt, which has been synthesized by reacting triphenylene hexathiol molecules (HTT) with PtCl2. At low elec-tron doping, the HTT-Pt converts from a normal insulator to a quantum spin Hall (QSH) insulator with time-reversal symmetry (TRS). At high electron doping, the TRS is further broken making the HTT-Pt a quantum anomalous Hall (QAH) insulator. The topologically nontrivial band gap of the electron-doped HTT-Pt opened by intrinsic spin-orbit coupling (SOC) can be as large as 44.5 meV, which is promising for realizing these quantum phases at high temperatures. The possibility of switching between the QSH and QAH states offers an intriguing platform for new device paradigm by interfacing between a QSH and QAH state.