Observation of topological pumping of a defect state in a Fock photonic lattice

Abstract

Topological pumping connects the topological features of a modulated system with its transport behavior. It provides a powerful means for robust topological transport between distant nodes even in a one-dimensional chain, which may find applications in wave manipulation and quantum information processing. Here, we experimentally demonstrate an adiabatic pumping scheme, topological pumping of a defect state, by introducing a Fock photonic lattice, which is a classical analog of the Fock-state lattice of the two-mode Jaynes-Cummings model. Since this pumping is always protected by an energy gap even for a large-size system, its pumping efficiency can be enhanced considerably compared with the conventional topological pumping schemes. Moreover, a topologically protected beam splitter is also realized by designing the pumping channels of a defect state. The experimental results agree well with theoretical simulations. Our scheme provides a different route to study topological transport and implement novel photonic devices.