Nontrivial Bloch oscillations in waveguide arrays with second-order coupling.
Under the influence of the next-nearest-neighbor interaction, we theoretically investigate the occurrence of Bloch oscillations in zigzag waveguide arrays. Because of the special topological configuration of the lattice itself, the second-order coupling (SOC) can be enhanced significantly and leads to the band alteration beyond the nearest-neighbor model, i.e., the offset of minimum value from the band edge. Contrary to the behavior in the vanishing SOC, the oscillation patterns exhibit new features, namely, a double turning-back occurs when the beam approaches the band edge. Our results can be applied to some ordered-lattice systems.
Wang
Gang
G
Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory of Micro and NanoPhotonic Structures (Ministry of Education), Fudan University, Shanghai, China. 071019009@fudan.edu.cn
Huang
Ji Ping
JP
Yu
Kin Wah
KW