Topological Phases of the Su-Schrieffer-Heeger Model Driven by Two Commensurate-Frequency Drives

Topological materials in Floquet (periodically driven) systems have attracted a great deal interest recently due to the ability to engineer topological phases by tuning the driving parameters. We study the physical and topological properties of the Su-Schrieffer-Heeger model driven by two time-dependent periodic sources with commensurate frequencies. The ability to introduce more than one driving frequency allows us to realize even more exotic topological phases resulting from new coupling appearing in the Fourier space representation. In order to compute the system topology in this space, we employ the local Chern marker, a real space representation of the well-known Chern number. Using this, we obtain topological phase diagrams and explore the phase boundaries resulting from new commensurate drives and demonstrate how this real-life experimental control can realize unique topological phases. We also calculate the current for a variety of cases in the time domain and we will discuss the implication of the current as it is related to topological phase transitions.