Conetronics in 2D metal-organic frameworks: double/half Dirac cones and quantum anomalous Hall effect

Abstract Bandstructure with Dirac cones gives rise to massless Dirac fermions with rich physics, and here we predict rich cone properties in M ₃ C ₁₂ S ₁₂ and M ₃ C ₁₂ O ₁₂ , where M = Zn, Cd, Hg, Be, or Mg based on recently synthesized Ni ₃ C ₁₂ S ₁₂ —class 2D metal-organic frameworks (MOFs). For M ₃ C ₁₂ S ₁₂ , their band structures exhibit double Dirac cones with different Fermi velocities that are n (electron) and p (hole) type, respectively, which are switchable by few-percent strain. The crossing of two cones are symmetry-protected to be non-hybridizing, leading to two independent channels at the same k -point akin to spin-channels in spintronics, rendering ‘conetronics’ device possible. For M ₃ C ₁₂ O ₁₂ , together with conjugated metal-tricatecholate polymers M ₃ (HHTP) ₂ , the spin-polarized slow Dirac cone center is pinned precisely at the Fermi level, making the systems conducting in only one spin/cone channel. Quantum anomalous Hall effect can arise in MOFs with non-negligible spin–orbit coupling like Cu ₃ C ₁₂ O ₁₂ . Compounds of M ₃ C ₁₂ S ₁₂ and M ₃ C ₁₂ O ₁₂ with different M , can be used to build spin/cone-selecting heterostructure devices tunable by strain or electrostatic gating, suggesting their potential applications in spintroincs/conetronics.