# Switchable phonon diodes using nonlinear topological Maxwell lattices

## TL;DR

This paper demonstrates how topological Maxwell lattices can be engineered to create tunable, non-reciprocal elastic wave transmission, functioning as phonon diodes with switchable behavior through topological phase transitions.

## Contribution

It introduces a novel design for topologically protected phonon diodes using nonlinear Maxwell lattices with switchable non-reciprocal wave transmission.

## Key findings

- Achieved non-reciprocal elastic wave transmission using topological floppy edge modes.
- Demonstrated switching of diode behavior via topological phase transitions.
- Proposed cellular metamaterials for tunable topologically protected phonon diodes.

## Abstract

Recent progress in topological mechanics have revealed a family of Maxwell lattices that exhibit topologically protected floppy edge modes. These modes lead to a strongly asymmetric elastic wave response. In this paper, we show how topological Maxwell lattices can be used to realize non-reciprocal transmission of elastic waves. Our design leverages the asymmetry associated with the availability of topological floppy edge modes and the geometric nonlinearity built in the mechanical systems response to achieve the desired non-reciprocal behavior, which can be further turned into strongly one-way phonon transport via the addition of on-site pinning potentials. Moreover, we show that the non-reciprocal wave transmission can be switched on and off via topological phase transitions, paving the way to the design of cellular metamaterials that can serve as tunable topologically protected phonon diodes.