2022/01/25 by Luke Thatcher, Parker Fairfield, Lázaro Merlo-Ramírez +2 · 34 citations
Materials Science · Physics and Astronomy · #Band gap #Condensed matter physics #Graphene research and applications #Phase (matter) #Phase transition #Physics #Quantum many-body systems #Quantum mechanics #String (physics) #Theoretical physics #Topological Materials and Phenomena #Topological insulator #Topological order #Topology (electrical circuits) #Work (physics)
paper · doi:10.1088/1402-4896/ac4ed2
published in Physica Scripta 97(3), 035702 (IOP Publishing)
openalex publication_date 2022/01/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Abstract In this work, we report the experimental observation of the topological phase transition in a mechanical one-dimensional topological insulator using the Su-Schrieffer-Heeger (SSH) model. Our mechanical system was composed of an elastic string with metallic masses emulating atomic sites and the intra- and inter-cell interaction strengths controlled by the distances, d 1 and d 2 respectively, between the masses. We observed a trivial phase with a band gap of ∼9.2 Hz ± 0.5 Hz for d 2 / d 1 = 3, while the metallic phase closed the gap, d 1 = d 2 , to be reopened in the topological phase as ∼8.7 Hz ± 0.5 Hz, for d 2 / d 1 = 1/3, with two edge states located inside the band gap at ∼15.6 Hz ± 0.5 Hz. Our experimental observations were supported with numerical and theoretical models. Our work creates the ability to study topological phase transitions in mechanical systems with materials available in any research lab and allows an understanding of phase transitions in a visual way.