Science Daily January 25, 2024
The concept of topological phases is rather abstract, and the characterization of the spectral topology of mechanical structures has intrinsically relied on the a priori knowledge of idealized theoretical models. An international team of researchers (USA – University of Pennsylvania, the Netherlands, France) introduced and validated an experimental method to detect the topologically protected zero modes of mechanical structures without resorting to any modeling step. The method is based on a simple electrostatic analogy: Topological zero modes are akin to electric charges. To detect them, they identified elementary mechanical molecules and measured their chiral polarization. Topological zero modes were then identified as singularities of the polarization field. According to the researchers their method can be applied to any mechanical structure to detect the edge and corner states of regular and higher-order topological insulators, and their findings extend the reach of chiral topological phases beyond designer materials and allow their direct experimental investigation… read more. Open Access TECHNICAL ARTICLE
Detecting topologically protected zero modes from poking experiments. Credit: PNAS, January 17, 2024, 121 (4) e2305287121