Experimental observation of topological phases in a longitudinal SSH mechanical model.

The SSH model [1] is one of the most important theoretical approaches to the study of topological properties of one-dimensional materials. We present the implementation of a mechanical topological insulator based on the SSH model. By modulating the elastic constant of a set of plastic slabs, we were able to demonstrate the topological phase transitions when the appropriate conditions were met under longitudinal modes. Our work generalizes the recently discovered universality of the critical exponents in a mechanical topological insulator when transverse waves were used [2].



[1] W. P. Su, et al. 1979 Phys. Rev. Lett. 42 1698–701

[2] L. Thatcher et al. 2022 Phys. Scr. 97, 035702