Page 03/22/2014 09:40:40

Paper accepted by Scientific Reports

​In this work, we used the perturbation method that was firstly proposed by us (PRB, 86, 035141) to study a double Dirac cone induced by accidental quadrupole-degenerate states in the center of the Brillouin zone.  The slope of the linear dispersion and the reduced Hamiltonian are derived.  Numerical simulation results show the unique wave propagation behaviors including the Talbot effect.  The paper is accepted by Scientific Reports, a journal publised by Nature Publishing Group, and the first-author is Zeguo Chen, an MS student.