Manipulation of Weyl Points in Reciprocal and Nonreciprocal Mechanical Lattices

TL;DR

This paper demonstrates the control and manipulation of Weyl points in mechanical lattices, including experimental realization of Weyl type I-II transition and effects of non-Hermiticity on topological surface states.

Contribution

It introduces feedback-measurement techniques for flexible control of Weyl points and experimentally demonstrates topological transitions in mechanical systems.

Findings

Weyl type I-II transition achieved experimentally.

Non-Hermiticity expands Fermi arc surface states.

Edge state localization influenced by band topology and skin effect.

Abstract

We introduce feedback-measurement technologies to achieve flexible control of Weyl points and conduct the first experimental demonstration of Weyl type I-II transition in mechanical systems. We demonstrate that non-Hermiticity can expand the Fermi arc surface states from connecting Weyl points to Weyl rings, and lead to a localization transition of edge states influenced by the interplay between band topology and the non-Hermitian skin effect. Our findings offer valuable insights into the design and manipulation of Weyl points in mechanical systems, providing a promising avenue for manipulating topological modes in non-Hermitian systems.