Reply to: “Topological and trivial domain wall states in engineered atomic chains”

Topological modes in one- and two-dimensional systems have been proposed for numerous applications utilizing their exotic electronic responses. Su-Schrieffer-Heeger (SSH) model–one-dimensional (1D) dimer chain–is one of the simplest models exhibiting topological states. While the edge modes in the SSH model are exactly at the mid-gap energy, other paradigmatic 1D models such as trimer and coupled dimer chains have non-zero energy boundary states. In our original paper 1 , we realized atomically controlled trimer and coupled dimer chains using chlorine vacancies in the c(2 × 2) adsorption layer on Cu(100) 2 . This built on earlier work on atomically controlled dimer chains 3 , where the desired structures are fabricated using atom manipulation by low-temperature scanning tunneling microscopy (STM).