Cheng Wenting, Prodan Emil, Prodan Camelia
Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102, USA.
Department of Physics, Yeshiva University, New York, New York 10016, USA.
Phys Rev Lett. 2020 Nov 27;125(22):224301. doi: 10.1103/PhysRevLett.125.224301.
A Thouless pump can be regarded as a dynamical version of the integer quantum Hall effect. In a finite-size configuration, such a topological pump displays edge modes that emerge dynamically from one bulk band and dive into the opposite bulk band, an effect that can be reproduced with both quantum and classical systems. Here, we report the first unassisted dynamic energy transfer across a metamaterial, via pumping of such topological edge modes. The system is a topological aperiodic acoustic crystal, with a phason that can be fast and periodically driven in adiabatic cycles. When one edge of the metamaterial is excited in a topological forbidden range of frequencies, a microphone placed at the other edge starts to pick up a signal as soon as the pumping process is set in motion. In contrast, the microphone picks no signal when the forbidden range of frequencies is nontopological.
一个 Thouless 泵可以被视为整数量子霍尔效应的动态版本。在有限尺寸配置中，这样的拓扑泵会展现出从一个体态能带动态出现并潜入相反体态能带的边缘模式，这种效应在量子和经典系统中都能再现。在此，我们报告了通过这种拓扑边缘模式的泵浦，首次在超材料中实现了无辅助的动态能量转移。该系统是一种拓扑非周期声学晶体，具有一个可以在绝热循环中被快速且周期性驱动的相位子。当超材料的一边在拓扑禁带频率范围内被激发时，一旦泵浦过程启动，放置在另一边的麦克风就会开始接收到信号。相比之下，当禁带频率范围是非拓扑的时候，麦克风接收不到信号。
