1301.5639 (Sriram Ganeshan et al.)

Z2 topological zero-energy modes in commensurate Aubry-André-Harper
models    [PDF]

Sriram Ganeshan, Kai Sun, S. Das Sarma

Aubry-Andr\'e (AA) model has been the subject of extensive theoretical research in the context of quantum localization. Recently, it is shown that one-dimensional quasicrystals described by the incommensurate Aubry-Andr\'e model has non-trivial topology. In this paper, we show that the commensurate off-diagonal Aubry-Andr\'e model is topologically nontrivial in the gapless regime and supports zero-energy edge modes with Z2 index. Unlike the incommensurate case, the nontrivial topology in the off-diagonal Aubry-Andr\'e model is attributed to the topological properties of the one-dimensional Majorana chain. We discuss the feasibility of experimental observability of our predicted Z2 topological phase.

View original: http://arxiv.org/abs/1301.5639