Topological Quantum Phase Transition of Light in Cavity QED Lattice

Our theoretical study shows the existence of topological quantum phase transition of light in Cavity QED lattice. We present the conditions for topological phase transition for three different model Hamiltonians in cavity QED lattice. We study these topological quantum phase transition through winding number calculation which is the first study in the literature. We show that the non-topological state is the vacuum state of the system where each cavity contains fermionic type excitations from light-matter interaction whereas the topological state of system contains Majorana modes of excitations at the two end points of cavity QED lattice.