1304.5012 (Tetsuro Habe)

Inter-surface interaction via phonon in three-dimensional topological
insulator    [PDF]

Tetsuro Habe

We theoretically study the effects of phonon in the inter-surface electron-electron interactions on the two surfaces of a three-dimensional topological insulator. The phonon excitation in the bulk plays an important role in mediating the inter-surface electron-electron interactions. We first derive the effective Lagrangian describing the two surface states with the interaction between them from a model of three dimensional topological insulator including the phonon excitation in it. The inter-surface electron-electron interaction can be either repulsive or attractive depending on parameters such as temperature, the speed of phonon, and the Fermi velocity of the surface states. The attractive interaction removes the Dirac nodes at the two surface states in association with the spontaneously symmetry breaking. On the basis of the calculated results, we also discuss how to tune the inter-surface interaction.

View original: http://arxiv.org/abs/1304.5012