<p>Worldwide there are significant efforts to build networks that can distribute photonic entanglement, first with applications in communication, with a long-term vision of constructing fully connected quantum processing networks (QPN). We have constructed a network of atom-light interfaces, providing a scalable QPN platform by creating connected room-temperature qubit memories using dark-state polaritons (DSPs). Furthermore, we combined ideas from two leading elements of quantum information namely collective enhancement effects of atomic ensembles and Cavity-QED to create a unique network element that can add quantum processing abilities to this network. We built a dual connection node consisting of two moderate finesse Fabry-Perot cavities. The cavities are configured to form a cross-cavity layout and coupled to a cold atomic ensemble. The physical regime of interest is the non-limiting case between (i) low N with high cooperativity and (ii) free-space-high-N ensembles. Lastly, we have explored how to use light-matter interfaces to implement an analog simulator of relativistic quantum particles following Dirac and Jackiw-Rebbi model Hamiltonians. Combining this development with the cross-cavity node provides a pathway towards quantum simulation of more complex phenomena involving interacting many quantum relativistic particles.