title: An analog of photon-assisted tunneling in a periodically modulated waveguide array.
abstract: We theoretically report an analog of photon-assisted tunneling (PAT) originated from dark Floquet state in a periodically driven lattice array without a static biased potential by studying a three-channel waveguide system in a non-high-frequency regime. This analog of PAT can be achieved by only periodically modulating the top waveguide and adjusting the distance between the bottom and its adjacent waveguide. It is numerically shown that the PAT resonances also exist in the five-channel waveguide system and probably exist in the waveguide arrays with other odd numbers of waveguides, but they will become weak as the number of waveguides increases. With origin different from traditional PAT, this type of PAT found in our work is closely linked to the existence of the zero-energy (dark) Floquet states. It is readily observable under currently accessible experimental conditions and may be useful for controlling light propagation in waveguide arrays.
authors: School of Physics, HUST, Wuhan 430074, People's Republic of China.
authors: Liping
authors: L
authors: Li
authors: Department of Physics, Jinggangshan University, Ji'an 343009, People's Republic of China.
authors: Xiaobing
authors: X
authors: Luo
authors: School of Physics, HUST, Wuhan 430074, People's Republic of China.
authors: Xiaoxue
authors: X
authors: Yang
authors: School of Physics, HUST, Wuhan 430074, People's Republic of China.
authors: Mei
authors: M
authors: Wang
authors: School of Physics, HUST, Wuhan 430074, People's Republic of China.
authors: Xinyou
authors: X
authors: Lü
authors: School of Physics, HUST, Wuhan 430074, People's Republic of China.
authors: Ying
authors: Y
authors: Wu