It has been widely accepted that silicene is a topological insulator, and its gap closes first and then opens again with increasing electric field, which indicates a topological phase transition from the quantum spin Hall state to the band insulator state. However, due to the relatively large atomic spacing of silicene, which reduces the bandwidth, the electron–electron interaction in this system is considerably strong and cannot be ignored. The Hubbard interaction, intrinsic spin orbital coupling(SOC), and electric field are taken into consideration in our tight-binding model, with which the phase diagram of silicene is carefully investigated on the mean field level. We have found that when the magnitudes of the two mass terms produced by the Hubbard interaction and electric potential are close to each other, the intrinsic SOC flips the sign of the mass term at either K or K for one spin and leads to the emergence of the spin-polarized quantum anomalous Hall state.
Carbon is extremely versatile in its ability to form a rich variety of allotropes with a wide range of fascinating properties.At ambient conditions graphite is the thermodynamically most stable carbon allotrope,and many structural transformations and modifications of carbon structures in various sp^2 and sp^3 bonding networks can be produced under various pressure and temperature conditions.For example,under
We propose an efficient implementation of combining dynamical mean field theory（DMFT） with electronic structural calculation based on the local density approximation（LDA）.The pseudo-potential-plane-wave method is used in the LDA part,which enables it to be applied to large systems.The full loop self consistency of the charge density has been reached in our implementation,which allows us to compute the total energy related properties.The procedure of LDA＋DMFT is introduced in detail with a complete flow chart.We have also applied our code to study the electronic structure of several typical strong correlated materials,including cerium,americium and NiO.Our results fit quite well with both the experimental data and previous studies.
