Self-induced Transparency in Flux Qubit Based Quantum Metamaterials: Dispersion Features

We considered the transparency of the electromagnetic pulse through superconducting flux qubit-based quantum metamaterial. We propose a setup comprised of an infinite chain of flux qubits embedded within the strip-line superconducting resonator. Our theoretical investigation implies that two types of hybrid matter - "light" waves govern the propagation of EM radiation through these media. These are polaritons and self-induced transparency solitons. The polariton spectrum consists of two branches separated by a relatively wide forbidden band. The soliton spectrum exhibits substantial dependence on pulse width. Thus, short pulses exhibit a simple, almost linear dispersion law typical for an empty transmission line. The dispersion law of wide pulses gradually deviates from the linear dependence as their widths increase. Finally, when pulse width overgrows critical value, the gap in the pulse spectrum appears. This implies possible dispersion-managed pulse transparency. In particular, soliton slowing down or even stopping may be achieved.