Topological interface states of surface water waves in a channel with heterojunctions

We propose a topological interface state in a water channel with heterojunctions, which is constructed by connecting two different periodically corrugated structures. The forbidden bands of periodic structures are classified by the Zak phase in one-dimensional system. It is found that not all heterojunctions can cause observable interface states, but they can only appear when the Zak phases of the two structures are different. When the interface states appear, we obtain a transmission peak in the forbidden band and observe the localization of wave energy. The experimental and numerical results confirm that topological interface states can exist in surface water waves when heterojunctions are formed by the combination of periodic channels with different Zak phases. The findings on topological interface states of water waves not only introduces the concepts of fundamental physics into the field of ocean engineering, but also provides different ideas for water wave manipulation and energy collection.(c) 2022 Elsevier B.V. All rights reserved.