A monolithic nonlinear transmission line system for the experimental study of lattice solitons

We describe a new method, applying molecular beam epitaxial (MBE) growth and microfabrication techniques, to experimentally model nonlinear phenomena. Specifically, we have built a periodically loaded monolithic nonlinear transmission line which has been fabricated on a specially designed MBE GaAs wafer to duplicate a theoretical physics model, the one-dimensional exponential lattice, which was proposed by Toda. An advantage of the current approach over previous lumped element circuits is that it precisely reproduces the physics of the model without depending upon mathematical manipulations and corrections. To accomplish this, the line capacitance and parasitic capacitance were canceled by proper design of the MBE wafer profile. The conditions required to apply this approach to other nonlinear systems have also been studied. The experimentally measured pulse shapes for the Toda soliton system were compared against calculated results, with good agreement.