Self-induced topological protection in nonlinear circuit arrays

The interplay between topology and many-body physics has been a topic of strong interest in condensed matter physics for several years. For electronic systems, research has so far focused on linear topological phenomena due to the lack of a proper experimental platform and, in classical systems, due to the weak nature of nonlinear phenomena. Recently, it has been shown, however, that nonlinear effects can lead to unique phenomena, including self-induced topological states. Here we report nonlinear circuit arrays that exhibit self-induced topological protection. Our arrays are based on one-dimensional transmission-line circuits that emulate the Su-Schrieffer-Heeger model. We show that these nonlinear circuit arrays can exhibit self-induced topological transitions as a function of the input intensity, leading to topologically robust edge states that are immune to the presence of defects. The emergence of these topological states could lead to the design of electronic, optical and acoustic devices with functionalities that are highly tolerant to fabrication imperfections and unwanted parasitic effects.