Gate-tunable phase transition in a bosonic Su-Schrieffer-Heeger chain

Abstract: 

Metamaterials engineered to host topological states of matter in controllable quantum systems might hold promise for advancement of quantum simulations quantum computing technologies. In this context, the Su-Schrieffer-Heeger (SSH) model has gained prominence due to its simplicity and practical applications, including entanglement stabilization in superconducting quantum circuits. Here, we present the implementation of a five-unit-cell bosonic SSH chain on a one-dimensional lattice of superconducting resonators. Our approach offers precise and independent in-situ tuning of coupling parameters – a feature that has eluded previous work. We achieve electrostatic control over the inductive intra-cell coupling using semiconductor nanowire junctions, which enables the spectroscopic observation of a trivial-to-topological phase transition in the engineered topological metamaterial. In particular, we will discuss the robustness of the topological edge state against various disorder realizations, including local perturbations and noise originating from electrostatic gate control. Our results pave the way for larger controllable bosonic lattices to facilitate quantum simulations.